diff --git a/bench/benchmarks/buffer.js b/bench/benchmarks/buffer.js
index 58a4ce291c2..3f4bc66389d 100644
--- a/bench/benchmarks/buffer.js
+++ b/bench/benchmarks/buffer.js
@@ -24,7 +24,7 @@ module.exports = function run() {
     const evented = new Evented();
 
     const stylesheetURL = `https://api.mapbox.com/styles/v1/mapbox/streets-v9?access_token=${accessToken}`;
-    ajax.getJSON(stylesheetURL, (err, stylesheet) => {
+    ajax.getJSON({ url: stylesheetURL }, (err, stylesheet) => {
         if (err) return evented.fire('error', {error: err});
 
         evented.fire('log', {
@@ -82,6 +82,12 @@ module.exports = function run() {
     return evented;
 };
 
+class StubMap extends Evented {
+    _transformRequest(url) {
+        return { url };
+    }
+}
+
 function preloadAssets(stylesheet, callback) {
     const assets = {
         glyphs: {},
@@ -89,7 +95,7 @@ function preloadAssets(stylesheet, callback) {
         tiles: {}
     };
 
-    const style = new Style(stylesheet);
+    const style = new Style(stylesheet, new StubMap());
 
     style.on('style.load', () => {
         function getGlyphs(params, callback) {
@@ -107,7 +113,7 @@ function preloadAssets(stylesheet, callback) {
         }
 
         function getTile(url, callback) {
-            ajax.getArrayBuffer(url, (err, response) => {
+            ajax.getArrayBuffer({ url }, (err, response) => {
                 assets.tiles[url] = response.data;
                 callback(err, response.data);
             });
diff --git a/bench/benchmarks/geojson_setdata_large.js b/bench/benchmarks/geojson_setdata_large.js
index 364dfe2c170..10f1df25541 100644
--- a/bench/benchmarks/geojson_setdata_large.js
+++ b/bench/benchmarks/geojson_setdata_large.js
@@ -14,7 +14,7 @@ module.exports = function() {
         evented.fire('log', {message: 'downloading large geojson'});
     }, 0);
 
-    ajax.getJSON('http://d2ad6b4ur7yvpq.cloudfront.net/naturalearth-3.3.0/ne_50m_land.geojson', (err, data) => {
+    ajax.getJSON({ url: 'http://d2ad6b4ur7yvpq.cloudfront.net/naturalearth-3.3.0/ne_50m_land.geojson' }, (err, data) => {
         evented.fire('log', {message: 'starting test'});
 
         if (err) return evented.fire('error', {error: err});
diff --git a/bench/benchmarks/style_load.js b/bench/benchmarks/style_load.js
index b026fa95c23..f08e527ca73 100644
--- a/bench/benchmarks/style_load.js
+++ b/bench/benchmarks/style_load.js
@@ -12,8 +12,13 @@ module.exports = function() {
 
     const evented = new Evented();
 
+    class StubMap extends Evented {
+        _transformRequest(url) {
+            return { url };
+        }
+    }
     const stylesheetURL = `https://api.mapbox.com/styles/v1/mapbox/streets-v9?access_token=${accessToken}`;
-    ajax.getJSON(stylesheetURL, (err, json) => {
+    ajax.getJSON({ url: stylesheetURL }, (err, json) => {
         if (err) {
             return evented.fire('error', {error: err});
         }
@@ -23,7 +28,7 @@ module.exports = function() {
 
         asyncTimesSeries(20, (callback) => {
             const timeStart = performance.now();
-            new Style(json)
+            new Style(json, new StubMap())
                 .on('error', (err) => {
                     evented.fire('error', { error: err });
                 })
diff --git a/src/source/geojson_source.js b/src/source/geojson_source.js
index 5cb6516c171..d73f4fb112b 100644
--- a/src/source/geojson_source.js
+++ b/src/source/geojson_source.js
@@ -4,6 +4,7 @@ const Evented = require('../util/evented');
 const util = require('../util/util');
 const window = require('../util/window');
 const EXTENT = require('../data/extent');
+const ResourceType = require('../util/ajax').ResourceType;
 
 import type {Source} from './source';
 import type Map from '../ui/map';
@@ -138,8 +139,8 @@ class GeoJSONSource extends Evented implements Source {
     }
 
     onAdd(map: Map) {
-        this.load();
         this.map = map;
+        this.load();
     }
 
     /**
@@ -170,7 +171,7 @@ class GeoJSONSource extends Evented implements Source {
         const options = util.extend({}, this.workerOptions);
         const data = this._data;
         if (typeof data === 'string') {
-            options.url = resolveURL(data);
+            options.request = this.map._transformRequest(resolveURL(data), ResourceType.Source);
         } else {
             options.data = JSON.stringify(data);
         }
diff --git a/src/source/geojson_worker_source.js b/src/source/geojson_worker_source.js
index 836daa6432d..96b4e930d24 100644
--- a/src/source/geojson_worker_source.js
+++ b/src/source/geojson_worker_source.js
@@ -18,11 +18,12 @@ import type {Actor} from '../util/actor';
 import type StyleLayerIndex from '../style/style_layer_index';
 
 import type {LoadVectorDataCallback} from './vector_tile_worker_source';
+import type {RequestParameters} from '../util/ajax';
 
 export type GeoJSON = Object;
 
 export type LoadGeoJSONParameters = {
-    url?: string,
+    request?: RequestParameters,
     data?: string,
     source: string,
     superclusterOptions?: Object,
@@ -164,8 +165,8 @@ class GeoJSONWorkerSource extends VectorTileWorkerSource {
         // origin or absolute path.
         // ie: /foo/bar.json or http://example.com/bar.json
         // but not ../foo/bar.json
-        if (params.url) {
-            ajax.getJSON(params.url, callback);
+        if (params.request) {
+            ajax.getJSON(params.request, callback);
         } else if (typeof params.data === 'string') {
             try {
                 return callback(null, JSON.parse(params.data));
diff --git a/src/source/image_source.js b/src/source/image_source.js
index c9a20cddfdb..e82d4954f65 100644
--- a/src/source/image_source.js
+++ b/src/source/image_source.js
@@ -91,7 +91,7 @@ class ImageSource extends Evented implements Source {
 
         this.url = this.options.url;
 
-        ajax.getImage(this.options.url, (err, image) => {
+        ajax.getImage(this.map._transformRequest(this.url, ajax.ResourceType.Image), (err, image) => {
             if (err) {
                 this.fire('error', {error: err});
             } else if (image) {
@@ -109,11 +109,8 @@ class ImageSource extends Evented implements Source {
     }
 
     onAdd(map: Map) {
-        this.load();
         this.map = map;
-        if (this.image) {
-            this.setCoordinates(this.coordinates);
-        }
+        this.load();
     }
 
     /**
@@ -181,7 +178,7 @@ class ImageSource extends Evented implements Source {
     }
 
     prepare() {
-        if (Object.keys(this.tiles).length === 0 === 0 || !this.image) return;
+        if (Object.keys(this.tiles).length === 0 || !this.image) return;
         this._prepareImage(this.map.painter.gl, this.image);
     }
 
@@ -230,7 +227,7 @@ class ImageSource extends Evented implements Source {
     serialize(): Object {
         return {
             type: 'image',
-            urls: this.url,
+            urls: this.options.url,
             coordinates: this.coordinates
         };
     }
diff --git a/src/source/load_tilejson.js b/src/source/load_tilejson.js
index e064c671b46..e49e228e4d3 100644
--- a/src/source/load_tilejson.js
+++ b/src/source/load_tilejson.js
@@ -5,7 +5,9 @@ const ajax = require('../util/ajax');
 const browser = require('../util/browser');
 const normalizeURL = require('../util/mapbox').normalizeSourceURL;
 
-module.exports = function(options: any, callback: Callback<TileJSON>) {
+import type {RequestTransformFunction} from '../ui/map';
+
+module.exports = function(options: any, requestTransformFn: RequestTransformFunction, callback: Callback<TileJSON>) {
     const loaded = function(err, tileJSON: any) {
         if (err) {
             return callback(err);
@@ -22,7 +24,7 @@ module.exports = function(options: any, callback: Callback<TileJSON>) {
     };
 
     if (options.url) {
-        ajax.getJSON(normalizeURL(options.url), loaded);
+        ajax.getJSON(requestTransformFn(normalizeURL(options.url), ajax.ResourceType.Source), loaded);
     } else {
         browser.frame(() => loaded(null, options));
     }
diff --git a/src/source/raster_tile_source.js b/src/source/raster_tile_source.js
index 0b8862a5f36..f3ce7cd0cd9 100644
--- a/src/source/raster_tile_source.js
+++ b/src/source/raster_tile_source.js
@@ -52,7 +52,7 @@ class RasterTileSource extends Evented implements Source {
 
     load() {
         this.fire('dataloading', {dataType: 'source'});
-        loadTileJSON(this._options, (err, tileJSON) => {
+        loadTileJSON(this._options, this.map._transformRequest, (err, tileJSON) => {
             if (err) {
                 this.fire('error', err);
             } else if (tileJSON) {
@@ -69,8 +69,8 @@ class RasterTileSource extends Evented implements Source {
     }
 
     onAdd(map: Map) {
-        this.load();
         this.map = map;
+        this.load();
     }
 
     setBounds(bounds?: [number, number, number, number]) {
@@ -91,7 +91,7 @@ class RasterTileSource extends Evented implements Source {
     loadTile(tile: Tile, callback: Callback<void>) {
         const url = normalizeURL(tile.coord.url(this.tiles, null, this.scheme), this.url, this.tileSize);
 
-        tile.request = ajax.getImage(url, (err, img) => {
+        tile.request = ajax.getImage(this.map._transformRequest(url, ajax.ResourceType.Tile), (err, img) => {
             delete tile.request;
 
             if (tile.aborted) {
diff --git a/src/source/rtl_text_plugin.js b/src/source/rtl_text_plugin.js
index db13b9fe2af..e9a6b88c2e8 100644
--- a/src/source/rtl_text_plugin.js
+++ b/src/source/rtl_text_plugin.js
@@ -38,7 +38,7 @@ module.exports.setRTLTextPlugin = function(pluginURL: string, callback: ErrorCal
     }
     pluginRequested = true;
     module.exports.errorCallback = callback;
-    ajax.getArrayBuffer(pluginURL, (err, response) => {
+    ajax.getArrayBuffer({ url: pluginURL }, (err, response) => {
         if (err) {
             callback(err);
         } else if (response) {
diff --git a/src/source/vector_tile_source.js b/src/source/vector_tile_source.js
index abf271cff1d..6e8c50dc2a7 100644
--- a/src/source/vector_tile_source.js
+++ b/src/source/vector_tile_source.js
@@ -5,6 +5,7 @@ const util = require('../util/util');
 const loadTileJSON = require('./load_tilejson');
 const normalizeURL = require('../util/mapbox').normalizeTileURL;
 const TileBounds = require('./tile_bounds');
+const ResourceType = require('../util/ajax').ResourceType;
 
 import type {Source} from './source';
 import type TileCoord from './tile_coord';
@@ -56,7 +57,7 @@ class VectorTileSource extends Evented implements Source {
     load() {
         this.fire('dataloading', {dataType: 'source'});
 
-        loadTileJSON(this._options, (err, tileJSON) => {
+        loadTileJSON(this._options, this.map._transformRequest, (err, tileJSON) => {
             if (err) {
                 this.fire('error', err);
             } else if (tileJSON) {
@@ -84,8 +85,8 @@ class VectorTileSource extends Evented implements Source {
     }
 
     onAdd(map: Map) {
-        this.load();
         this.map = map;
+        this.load();
     }
 
     serialize() {
@@ -94,8 +95,9 @@ class VectorTileSource extends Evented implements Source {
 
     loadTile(tile: Tile, callback: Callback<void>) {
         const overscaling = tile.coord.z > this.maxzoom ? Math.pow(2, tile.coord.z - this.maxzoom) : 1;
+        const url = normalizeURL(tile.coord.url(this.tiles, this.maxzoom, this.scheme), this.url);
         const params = {
-            url: normalizeURL(tile.coord.url(this.tiles, this.maxzoom, this.scheme), this.url),
+            request: this.map._transformRequest(url, ResourceType.Tile),
             uid: tile.uid,
             coord: tile.coord,
             zoom: tile.coord.z,
diff --git a/src/source/vector_tile_worker_source.js b/src/source/vector_tile_worker_source.js
index dbd3c028abf..c225aebd46a 100644
--- a/src/source/vector_tile_worker_source.js
+++ b/src/source/vector_tile_worker_source.js
@@ -40,7 +40,7 @@ export type LoadVectorData = (params: WorkerTileParameters, callback: LoadVector
  * @private
  */
 function loadVectorTile(params: WorkerTileParameters, callback: LoadVectorDataCallback) {
-    const xhr = ajax.getArrayBuffer(params.url, (err, response) => {
+    const xhr = ajax.getArrayBuffer(params.request, (err, response) => {
         if (err) {
             callback(err);
         } else if (response) {
diff --git a/src/source/video_source.js b/src/source/video_source.js
index 47c874da1bb..e0cda3f6504 100644
--- a/src/source/video_source.js
+++ b/src/source/video_source.js
@@ -96,8 +96,8 @@ class VideoSource extends ImageSource {
 
     onAdd(map: Map) {
         if (this.map) return;
-        this.load();
         this.map = map;
+        this.load();
         if (this.video) {
             this.video.play();
             this.setCoordinates(this.coordinates);
diff --git a/src/source/worker.js b/src/source/worker.js
index 58ca20bb49e..15fb4dd43ed 100644
--- a/src/source/worker.js
+++ b/src/source/worker.js
@@ -108,7 +108,7 @@ class Worker {
      * function taking `(name, workerSourceObject)`.
      *  @private
      */
-    loadWorkerSource(map: string, params: {url: string}, callback: Callback<void>) {
+    loadWorkerSource(map: string, params: { url: string }, callback: Callback<void>) {
         try {
             this.self.importScripts(params.url);
             callback();
diff --git a/src/source/worker_source.js b/src/source/worker_source.js
index a444ce25d11..7296fb8975d 100644
--- a/src/source/worker_source.js
+++ b/src/source/worker_source.js
@@ -7,6 +7,7 @@ import type {SerializedBucket} from '../data/bucket';
 import type {SerializedFeatureIndex} from '../data/feature_index';
 import type {SerializedCollisionTile} from '../symbol/collision_tile';
 import type {SerializedStructArray} from '../util/struct_array';
+import type {RequestParameters} from '../util/ajax';
 
 export type TileParameters = {
     source: string,
@@ -23,7 +24,7 @@ export type PlacementConfig = {
 
 export type WorkerTileParameters = TileParameters & {
     coord: TileCoord,
-    url: string,
+    request: RequestParameters,
     zoom: number,
     maxZoom: number,
     tileSize: number,
diff --git a/src/style/image_sprite.js b/src/style/image_sprite.js
index 78d847b9465..dcdfa786e2c 100644
--- a/src/style/image_sprite.js
+++ b/src/style/image_sprite.js
@@ -5,6 +5,8 @@ const ajax = require('../util/ajax');
 const browser = require('../util/browser');
 const normalizeURL = require('../util/mapbox').normalizeSpriteURL;
 
+import type {RequestTransformFunction} from '../ui/map';
+
 class SpritePosition {
     x: number;
     y: number;
@@ -27,19 +29,22 @@ class ImageSprite extends Evented {
     base: string;
     retina: boolean;
 
+    transformRequestFn: RequestTransformFunction;
     data: ?{[string]: SpritePosition};
     imgData: ?Uint8ClampedArray;
     width: ?number;
 
-    constructor(base: string, eventedParent?: Evented) {
+    constructor(base: string, transformRequestCallback: RequestTransformFunction, eventedParent?: Evented) {
         super();
         this.base = base;
         this.retina = browser.devicePixelRatio > 1;
         this.setEventedParent(eventedParent);
+        this.transformRequestFn = transformRequestCallback;
 
         const format = this.retina ? '@2x' : '';
-
-        ajax.getJSON(normalizeURL(base, format, '.json'), (err, data) => {
+        let url = normalizeURL(base, format, '.json');
+        const jsonRequest = transformRequestCallback(url, ajax.ResourceType.SpriteJSON);
+        ajax.getJSON(jsonRequest, (err, data) => {
             if (err) {
                 this.fire('error', {error: err});
             } else if (data) {
@@ -47,8 +52,9 @@ class ImageSprite extends Evented {
                 if (this.imgData) this.fire('data', {dataType: 'style'});
             }
         });
-
-        ajax.getImage(normalizeURL(base, format, '.png'), (err, img) => {
+        url = normalizeURL(base, format, '.png');
+        const imageRequest = transformRequestCallback(url, ajax.ResourceType.SpriteImage);
+        ajax.getImage(imageRequest, (err, img) => {
             if (err) {
                 this.fire('error', {error: err});
             } else if (img) {
@@ -71,7 +77,7 @@ class ImageSprite extends Evented {
 
     resize(/*gl*/) {
         if (browser.devicePixelRatio > 1 !== this.retina) {
-            const newSprite = new ImageSprite(this.base);
+            const newSprite = new ImageSprite(this.base, this.transformRequestFn);
             newSprite.on('data', () => {
                 this.data = newSprite.data;
                 this.imgData = newSprite.imgData;
diff --git a/src/style/style.js b/src/style/style.js
index 43f1787b045..3ba70b80025 100644
--- a/src/style/style.js
+++ b/src/style/style.js
@@ -85,6 +85,10 @@ class Style extends Evented {
             }
         });
 
+        const transformRequest = (url, resourceType) => {
+            return  this.map ? this.map._transformRequest(url, resourceType) : { url };
+        };
+
         const stylesheetLoaded = (err, stylesheet) => {
             if (err) {
                 this.fire('error', {error: err});
@@ -103,17 +107,17 @@ class Style extends Evented {
             }
 
             if (stylesheet.sprite) {
-                this.sprite = new ImageSprite(stylesheet.sprite, this);
+                this.sprite = new ImageSprite(stylesheet.sprite, transformRequest, this);
             }
 
-            this.glyphSource = new GlyphSource(stylesheet.glyphs, options.localIdeographFontFamily, this);
+            this.glyphSource = new GlyphSource(stylesheet.glyphs, options.localIdeographFontFamily, transformRequest, this);
             this._resolve();
             this.fire('data', {dataType: 'style'});
             this.fire('style.load');
         };
 
         if (typeof stylesheet === 'string') {
-            ajax.getJSON(mapbox.normalizeStyleURL(stylesheet), stylesheetLoaded);
+            ajax.getJSON(transformRequest(mapbox.normalizeStyleURL(stylesheet), ajax.ResourceType.Style), stylesheetLoaded);
         } else {
             browser.frame(stylesheetLoaded.bind(this, null, stylesheet));
         }
diff --git a/src/symbol/glyph_source.js b/src/symbol/glyph_source.js
index df04c2f7eae..f0e0743a7aa 100644
--- a/src/symbol/glyph_source.js
+++ b/src/symbol/glyph_source.js
@@ -11,6 +11,7 @@ const Evented = require('../util/evented');
 
 import type {Glyph, GlyphStack} from '../util/glyphs';
 import type {Rect} from '../symbol/glyph_atlas';
+import type {RequestTransformFunction} from '../ui/map';
 
 // A simplified representation of the glyph containing only the properties needed for shaping.
 class SimpleGlyph {
@@ -42,11 +43,12 @@ class GlyphSource extends Evented {
     loading: {[string]: {[number]: Array<Function>}};
     localIdeographFontFamily: string;
     tinySDFs: {[string]: TinySDF};
+    transformRequestCallback: RequestTransformFunction;
 
     /**
      * @param {string} url glyph template url
      */
-    constructor(url: string, localIdeographFontFamily: string, eventedParent?: Evented) {
+    constructor(url: string, localIdeographFontFamily: string, transformRequestCallback: RequestTransformFunction, eventedParent?: Evented) {
         super();
         this.url = url && normalizeURL(url);
         this.atlases = {};
@@ -55,6 +57,7 @@ class GlyphSource extends Evented {
         this.localIdeographFontFamily = localIdeographFontFamily;
         this.tinySDFs = {};
         this.setEventedParent(eventedParent);
+        this.transformRequestCallback = transformRequestCallback;
     }
 
     getSimpleGlyphs(fontstack: string, glyphIDs: Array<number>, uid: number, callback: (err: ?Error, glyphs: {[number]: SimpleGlyph}, fontstack: string) => void) {
@@ -163,7 +166,8 @@ class GlyphSource extends Evented {
     }
 
     loadPBF(url: string, callback: Callback<{data: ArrayBuffer}>) {
-        ajax.getArrayBuffer(url, callback);
+        const request  = this.transformRequestCallback ? this.transformRequestCallback(url, ajax.ResourceType.Glyphs) : { url };
+        ajax.getArrayBuffer(request, callback);
     }
 
     loadRange(fontstack: string, range: number, callback: (err: ?Error, range: ?number, glyphs: ?Glyphs) => void) {
diff --git a/src/ui/map.js b/src/ui/map.js
index 9599f069f9f..fdf718b9c37 100755
--- a/src/ui/map.js
+++ b/src/ui/map.js
@@ -25,6 +25,7 @@ const isSupported = require('mapbox-gl-supported');
 
 import type {LngLatLike} from '../geo/lng_lat';
 import type {LngLatBoundsLike} from '../geo/lng_lat_bounds';
+import type {RequestParameters} from '../util/ajax';
 
 /* eslint-disable no-use-before-define */
 type IControl = {
@@ -33,6 +34,9 @@ type IControl = {
 }
 /* eslint-enable no-use-before-define */
 
+type ResourceTypeEnum = $Keys<typeof ajax.ResourceType>;
+export type RequestTransformFunction = (url: string, resourceType?: ResourceTypeEnum) => RequestParameters;
+
 type MapOptions = {
     hash?: boolean,
     interactive?: boolean,
@@ -60,7 +64,8 @@ type MapOptions = {
     bearing?: number,
     pitch?: number,
     renderWorldCopies?: boolean,
-    maxTileCacheSize?: number
+    maxTileCacheSize?: number,
+    transformRequest?: RequestTransformFunction
 };
 
 type MapEvent =
@@ -125,7 +130,9 @@ const defaultOptions = {
 
     refreshExpiredTiles: true,
 
-    maxTileCacheSize: null
+    maxTileCacheSize: null,
+
+    transformRequest: null
 };
 
 /**
@@ -196,13 +203,24 @@ const defaultOptions = {
  *   for locally overriding generation of glyphs in the 'CJK Unified Ideographs' and 'Hangul Syllables' ranges.
  *   In these ranges, font settings from the map's style will be ignored, except for font-weight keywords (light/regular/medium/bold).
  *   The purpose of this option is to avoid bandwidth-intensive glyph server requests. (see [Use locally generated ideographs](https://www.mapbox.com/mapbox-gl-js/example/local-ideographs))
+ * @param {RequestTransformFunction} [options.transformRequest=null] A callback run before the Map makes a request for an external URL. The callback can be used to modify the url, set headers, or set the credentials property for cross-origin requests.
+ *   Expected to return an object with a `url` property and optionally `headers` and `credentials` properties.
  * @example
  * var map = new mapboxgl.Map({
  *   container: 'map',
  *   center: [-122.420679, 37.772537],
  *   zoom: 13,
  *   style: style_object,
- *   hash: true
+ *   hash: true,
+ *   transformRequest: (url, resourceType)=> {
+ *     if(resourceType == 'Source' && url.startsWith('http://myHost') {
+ *       return {
+ *        url: url.replace('http', 'https'),
+ *        headers: { 'my-custom-header': true},
+ *        credentials: 'include'  // Include cookies for cross-origin requests
+ *      }
+ *     }
+ *   }
  * });
  * @see [Display a map](https://www.mapbox.com/mapbox-gl-js/examples/)
  */
@@ -221,6 +239,7 @@ class Map extends Camera {
     _repaint: ?boolean;
     _vertices: ?boolean;
     _canvas: HTMLCanvasElement;
+    _transformRequest: RequestTransformFunction;
 
     constructor(options: MapOptions) {
         options = util.extend({}, defaultOptions, options);
@@ -240,6 +259,9 @@ class Map extends Camera {
         this._bearingSnap = options.bearingSnap;
         this._refreshExpiredTiles = options.refreshExpiredTiles;
 
+        const transformRequestFn = options.transformRequest;
+        this._transformRequest = transformRequestFn ?  (url, type) => transformRequestFn(url, type) || ({ url }) : (url) => ({ url });
+
         if (typeof options.container === 'string') {
             this._container = window.document.getElementById(options.container);
             if (!this._container) throw new Error(`Container '${options.container}' not found.`);
@@ -1134,7 +1156,7 @@ class Map extends Camera {
      * @see [Add an icon to the map](https://www.mapbox.com/mapbox-gl-js/example/add-image/)
      */
     loadImage(url: string, callback: Function) {
-        ajax.getImage(url, callback);
+        ajax.getImage(this._transformRequest(url, ajax.ResourceType.Image), callback);
     }
 
     /**
diff --git a/src/util/ajax.js b/src/util/ajax.js
index c01e25f91e0..1425af84ce2 100644
--- a/src/util/ajax.js
+++ b/src/util/ajax.js
@@ -2,6 +2,41 @@
 
 const window = require('./window');
 
+/**
+ * The type of a resource.
+ * @private
+ * @readonly
+ * @enum {string}
+ */
+const ResourceType = {
+    Unknown: 'Unknown',
+    Style: 'Style',
+    Source: 'Source',
+    Tile: 'Tile',
+    Glyphs: 'Glyphs',
+    SpriteImage: 'SpriteImage',
+    SpriteJSON: 'SpriteJSON',
+    Image: 'Image'
+};
+exports.ResourceType = ResourceType;
+
+if (typeof Object.freeze == 'function') {
+    Object.freeze(ResourceType);
+}
+
+/**
+ * A `RequestParameters` object to be returned from Map.options.transformRequest callbacks.
+ * @typedef {Object} RequestParameters
+ * @property {string} url The URL to be requested.
+ * @property {Object} headers The headers to be sent with the request.
+ * @property {string} credentials `'same-origin'|'include'` Use 'include' to send cookies with cross-origin requests.
+ */
+export type RequestParameters = {
+    url: string,
+    headers?: Object,
+    credentials? : 'same-origin' | 'include'
+};
+
 class AJAXError extends Error {
     status: number;
     constructor(message: string, status: number) {
@@ -10,9 +45,19 @@ class AJAXError extends Error {
     }
 }
 
-exports.getJSON = function(url: string, callback: Callback<mixed>) {
+function makeRequest(requestParameters: RequestParameters) : XMLHttpRequest {
     const xhr: XMLHttpRequest = new window.XMLHttpRequest();
-    xhr.open('GET', url, true);
+
+    xhr.open('GET', requestParameters.url, true);
+    for (const k in requestParameters.headers) {
+        xhr.setRequestHeader(k, requestParameters.headers[k]);
+    }
+    xhr.withCredentials = requestParameters.credentials === 'include';
+    return xhr;
+}
+
+exports.getJSON = function(requestParameters: RequestParameters, callback: Callback<mixed>) {
+    const xhr = makeRequest(requestParameters);
     xhr.setRequestHeader('Accept', 'application/json');
     xhr.onerror = function() {
         callback(new Error(xhr.statusText));
@@ -34,9 +79,8 @@ exports.getJSON = function(url: string, callback: Callback<mixed>) {
     return xhr;
 };
 
-exports.getArrayBuffer = function(url: string, callback: Callback<{data: ArrayBuffer, cacheControl: ?string, expires: ?string}>) {
-    const xhr: XMLHttpRequest = new window.XMLHttpRequest();
-    xhr.open('GET', url, true);
+exports.getArrayBuffer = function(requestParameters: RequestParameters, callback: Callback<{data: ArrayBuffer, cacheControl: ?string, expires: ?string}>) {
+    const xhr = makeRequest(requestParameters);
     xhr.responseType = 'arraybuffer';
     xhr.onerror = function() {
         callback(new Error(xhr.statusText));
@@ -68,10 +112,10 @@ function sameOrigin(url) {
 
 const transparentPngUrl = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAC0lEQVQYV2NgAAIAAAUAAarVyFEAAAAASUVORK5CYII=';
 
-exports.getImage = function(url: string, callback: Callback<HTMLImageElement>) {
+exports.getImage = function(requestParameters: RequestParameters, callback: Callback<HTMLImageElement>) {
     // request the image with XHR to work around caching issues
     // see https://github.com/mapbox/mapbox-gl-js/issues/1470
-    return exports.getArrayBuffer(url, (err, imgData) => {
+    return exports.getArrayBuffer(requestParameters, (err, imgData) => {
         if (err) {
             callback(err);
         } else if (imgData) {
diff --git a/test/suite_implementation.js b/test/suite_implementation.js
index 8d6a60e170e..4ccf8a04c4b 100644
--- a/test/suite_implementation.js
+++ b/test/suite_implementation.js
@@ -126,7 +126,7 @@ function cached(data, callback) {
     });
 }
 
-sinon.stub(ajax, 'getJSON').callsFake((url, callback) => {
+sinon.stub(ajax, 'getJSON').callsFake(({ url }, callback) => {
     if (cache[url]) return cached(cache[url], callback);
     return request(url, (error, response, body) => {
         if (!error && response.statusCode >= 200 && response.statusCode < 300) {
@@ -144,9 +144,9 @@ sinon.stub(ajax, 'getJSON').callsFake((url, callback) => {
     });
 });
 
-sinon.stub(ajax, 'getArrayBuffer').callsFake((url, callback) => {
+sinon.stub(ajax, 'getArrayBuffer').callsFake(({ url }, callback) => {
     if (cache[url]) return cached(cache[url], callback);
-    return request({url: url, encoding: null}, (error, response, body) => {
+    return request({ url, encoding: null }, (error, response, body) => {
         if (!error && response.statusCode >= 200 && response.statusCode < 300) {
             cache[url] = {data: body};
             callback(null, {data: body});
@@ -156,9 +156,9 @@ sinon.stub(ajax, 'getArrayBuffer').callsFake((url, callback) => {
     });
 });
 
-sinon.stub(ajax, 'getImage').callsFake((url, callback) => {
+sinon.stub(ajax, 'getImage').callsFake(({ url }, callback) => {
     if (cache[url]) return cached(cache[url], callback);
-    return request({url: url, encoding: null}, (error, response, body) => {
+    return request({ url, encoding: null }, (error, response, body) => {
         if (!error && response.statusCode >= 200 && response.statusCode < 300) {
             new PNG().parse(body, (err, png) => {
                 if (err) return callback(err);
@@ -178,7 +178,7 @@ sinon.stub(browser, 'getImageData').callsFake((img) => {
 // Hack: since node doesn't have any good video codec modules, just grab a png with
 // the first frame and fake the video API.
 sinon.stub(ajax, 'getVideo').callsFake((urls, callback) => {
-    return request({url: urls[0], encoding: null}, (error, response, body) => {
+    return request({ url: urls[0], encoding: null }, (error, response, body) => {
         if (!error && response.statusCode >= 200 && response.statusCode < 300) {
             new PNG().parse(body, (err, png) => {
                 if (err) return callback(err);
diff --git a/test/unit/source/geojson_source.test.js b/test/unit/source/geojson_source.test.js
index 8ee875411e2..71d6d4baabd 100644
--- a/test/unit/source/geojson_source.test.js
+++ b/test/unit/source/geojson_source.test.js
@@ -139,6 +139,17 @@ test('GeoJSONSource#update', (t) => {
         }, mockDispatcher).load();
     });
 
+    t.test('transforms url before making request', (t) => {
+        const mapStub = {
+            _transformRequest: (url) => { return { url }; }
+        };
+        const transformSpy = t.spy(mapStub, '_transformRequest');
+        const source = new GeoJSONSource('id', {data: 'https://example.com/data.geojson'}, mockDispatcher);
+        source.onAdd(mapStub);
+        t.ok(transformSpy.calledOnce);
+        t.equal(transformSpy.getCall(0).args[0], 'https://example.com/data.geojson');
+        t.end();
+    });
     t.test('fires event when metadata loads', (t) => {
         const mockDispatcher = {
             send: function(message, args, callback) {
@@ -202,9 +213,12 @@ test('GeoJSONSource#update', (t) => {
 });
 
 test('GeoJSONSource#serialize', (t) => {
-
+    const mapStub = {
+        _transformRequest: (url) => { return { url }; }
+    };
     t.test('serialize source with inline data', (t) => {
         const source = new GeoJSONSource('id', {data: hawkHill}, mockDispatcher);
+        source.map = mapStub;
         source.load();
         t.deepEqual(source.serialize(), {
             type: 'geojson',
@@ -215,6 +229,7 @@ test('GeoJSONSource#serialize', (t) => {
 
     t.test('serialize source with url', (t) => {
         const source = new GeoJSONSource('id', {data: 'local://data.json'}, mockDispatcher);
+        source.map = mapStub;
         source.load();
         t.deepEqual(source.serialize(), {
             type: 'geojson',
@@ -225,6 +240,7 @@ test('GeoJSONSource#serialize', (t) => {
 
     t.test('serialize source with updated data', (t) => {
         const source = new GeoJSONSource('id', {data: {}}, mockDispatcher);
+        source.map = mapStub;
         source.load();
         source.setData(hawkHill);
         t.deepEqual(source.serialize(), {
diff --git a/test/unit/source/image_source.test.js b/test/unit/source/image_source.test.js
new file mode 100644
index 00000000000..d4735e518b2
--- /dev/null
+++ b/test/unit/source/image_source.test.js
@@ -0,0 +1,96 @@
+'use strict';
+
+const test = require('mapbox-gl-js-test').test;
+const ImageSource = require('../../../src/source/image_source');
+const Evented = require('../../../src/util/evented');
+const Transform = require('../../../src/geo/transform');
+const util = require('../../../src/util/util');
+const ajax = require('../../../src/util/ajax');
+
+function createSource(options) {
+    options = util.extend({
+        coordinates: [[0, 0], [1, 0], [1, 1], [0, 1]]
+    }, options);
+
+    const source = new ImageSource('id', options, { send: function() {} }, options.eventedParent);
+    return source;
+}
+
+class StubMap extends Evented {
+    constructor() {
+        super();
+        this.transform = new Transform();
+    }
+
+    _transformRequest(url) {
+        return { url };
+    }
+}
+
+test('ImageSource', (t) => {
+
+    t.stub(ajax, 'getImage').callsFake((params, callback) => { callback(null, new ArrayBuffer(1)); });
+
+    t.test('constructor', (t) => {
+        const source = createSource({ url : '/image.png' });
+
+        t.equal(source.minzoom, 0);
+        t.equal(source.maxzoom, 22);
+        t.equal(source.tileSize, 512);
+        t.end();
+    });
+
+    t.test('fires dataloading event', (t) => {
+        const source = createSource({ url : '/image.png' });
+        source.on('dataloading', (e) => {
+            t.equal(e.dataType, 'source');
+            t.end();
+        });
+        source.onAdd(new StubMap());
+    });
+
+    t.test('transforms url request', (t) => {
+        const source = createSource({ url : '/image.png' });
+        const map = new StubMap();
+        const spy = t.spy(map, '_transformRequest');
+        source.onAdd(map);
+        t.ok(spy.calledOnce);
+        t.equal(spy.getCall(0).args[0], '/image.png');
+        t.equal(spy.getCall(0).args[1], 'Image');
+        t.end();
+    });
+
+    t.test('fires data event when content is loaded', (t) => {
+        const source = createSource({ url : '/image.png' });
+        source.on('data', (e) => {
+            if (e.dataType === 'source' && e.sourceDataType === 'content') {
+                t.ok(typeof source.coord == 'object');
+                t.end();
+            }
+        });
+        source.onAdd(new StubMap());
+    });
+
+    t.test('fires data event when metadata is loaded', (t) => {
+        const source = createSource({ url : '/image.png' });
+        source.on('data', (e) => {
+            if (e.dataType === 'source' && e.sourceDataType === 'metadata') {
+                t.end();
+            }
+        });
+        source.onAdd(new StubMap());
+    });
+
+    t.test('serialize url and coordinates', (t) => {
+        const source = createSource({ url: '/image.png' });
+
+        const serialized = source.serialize();
+        t.equal(serialized.type, 'image');
+        t.equal(serialized.urls, '/image.png');
+        t.deepEqual(serialized.coordinates, [[0, 0], [1, 0], [1, 1], [0, 1]]);
+
+        t.end();
+    });
+
+    t.end();
+});
diff --git a/test/unit/source/raster_tile_source.test.js b/test/unit/source/raster_tile_source.test.js
index c19c34ac4d5..eaa3ae93812 100644
--- a/test/unit/source/raster_tile_source.test.js
+++ b/test/unit/source/raster_tile_source.test.js
@@ -2,12 +2,13 @@
 const test = require('mapbox-gl-js-test').test;
 const RasterTileSource = require('../../../src/source/raster_tile_source');
 const window = require('../../../src/util/window');
+const TileCoord = require('../../../src/source/tile_coord');
 
-
-function createSource(options) {
+function createSource(options, transformCallback) {
     const source = new RasterTileSource('id', options, { send: function() {} }, options.eventedParent);
     source.onAdd({
-        transform: { angle: 0, pitch: 0, showCollisionBoxes: false }
+        transform: { angle: 0, pitch: 0, showCollisionBoxes: false },
+        _transformRequest: transformCallback ? transformCallback : (url) => { return { url }; }
     });
 
     source.on('error', (e) => {
@@ -28,6 +29,26 @@ test('RasterTileSource', (t) => {
         callback();
     });
 
+    t.test('transforms request for TileJSON URL', (t) => {
+        window.server.respondWith('/source.json', JSON.stringify({
+            minzoom: 0,
+            maxzoom: 22,
+            attribution: "Mapbox",
+            tiles: ["http://example.com/{z}/{x}/{y}.png"],
+            bounds: [-47, -7, -45, -5]
+        }));
+        const transformSpy = t.spy((url) => {
+            return { url };
+        });
+
+        createSource({ url: "/source.json" }, transformSpy);
+        window.server.respond();
+
+        t.equal(transformSpy.getCall(0).args[0], '/source.json');
+        t.equal(transformSpy.getCall(0).args[1], 'Source');
+        t.end();
+    });
+
     t.test('respects TileJSON.bounds', (t)=>{
         const source = createSource({
             minzoom: 0,
@@ -72,6 +93,34 @@ test('RasterTileSource', (t) => {
         });
         window.server.respond();
     });
+
+    t.test('transforms tile urls before requesting', (t) => {
+        window.server.respondWith('/source.json', JSON.stringify({
+            minzoom: 0,
+            maxzoom: 22,
+            attribution: "Mapbox",
+            tiles: ["http://example.com/{z}/{x}/{y}.png"],
+            bounds: [-47, -7, -45, -5]
+        }));
+        const source = createSource({ url: "/source.json" });
+        const transformSpy = t.spy(source.map, '_transformRequest');
+        source.on('data', (e) => {
+            if (e.sourceDataType === 'metadata') {
+                const tile = {
+                    coord: new TileCoord(10, 5, 5, 0),
+                    state: 'loading',
+                    loadVectorData: function () {},
+                    setExpiryData: function() {}
+                };
+                source.loadTile(tile, () => {});
+                t.ok(transformSpy.calledOnce);
+                t.equal(transformSpy.getCall(0).args[0], 'http://example.com/10/5/5.png');
+                t.equal(transformSpy.getCall(0).args[1], 'Tile');
+                t.end();
+            }
+        });
+        window.server.respond();
+    });
     t.end();
 
 });
diff --git a/test/unit/source/tile.test.js b/test/unit/source/tile.test.js
index af2a42aeb44..c08cf4302ca 100644
--- a/test/unit/source/tile.test.js
+++ b/test/unit/source/tile.test.js
@@ -61,7 +61,7 @@ test('querySourceFeatures', (t) => {
         geojsonWrapper.name = '_geojsonTileLayer';
         tile.rawTileData = vtpbf({ layers: { '_geojsonTileLayer': geojsonWrapper }});
         result = [];
-        t.doesNotThrow(tile.querySourceFeatures(result));
+        t.doesNotThrow(() => { tile.querySourceFeatures(result); });
         t.equal(result.length, 0);
         t.end();
     });
diff --git a/test/unit/source/vector_tile_source.test.js b/test/unit/source/vector_tile_source.test.js
index 3cb8cc23645..be999c7598f 100644
--- a/test/unit/source/vector_tile_source.test.js
+++ b/test/unit/source/vector_tile_source.test.js
@@ -6,10 +6,11 @@ const TileCoord = require('../../../src/source/tile_coord');
 const window = require('../../../src/util/window');
 const Evented = require('../../../src/util/evented');
 
-function createSource(options) {
+function createSource(options, transformCallback) {
     const source = new VectorTileSource('id', options, { send: function() {} }, options.eventedParent);
     source.onAdd({
-        transform: { angle: 0, pitch: 0, cameraToCenterDistance: 1, cameraToTileDistance: () => { return 1; }, showCollisionBoxes: false }
+        transform: { angle: 0, pitch: 0, cameraToCenterDistance: 1, cameraToTileDistance: () => { return 1; }, showCollisionBoxes: false },
+        _transformRequest: transformCallback ? transformCallback : (url) => { return { url }; }
     });
 
     source.on('error', (e) => {
@@ -68,6 +69,19 @@ test('VectorTileSource', (t) => {
         window.server.respond();
     });
 
+    t.test('transforms the request for TileJSON URL', (t) => {
+        window.server.respondWith('/source.json', JSON.stringify(require('../../fixtures/source')));
+        const transformSpy = t.spy((url) => {
+            return { url };
+        });
+
+        createSource({ url: "/source.json" }, transformSpy);
+        window.server.respond();
+        t.equal(transformSpy.getCall(0).args[0], '/source.json');
+        t.equal(transformSpy.getCall(0).args[1], 'Source');
+        t.end();
+    });
+
     t.test('fires event with metadata property', (t) => {
         window.server.respondWith('/source.json', JSON.stringify(require('../../fixtures/source')));
         const source = createSource({ url: "/source.json" });
@@ -134,7 +148,7 @@ test('VectorTileSource', (t) => {
 
             source.dispatcher.send = function(type, params) {
                 t.equal(type, 'loadTile');
-                t.equal(expectedURL, params.url);
+                t.equal(expectedURL, params.request.url);
                 t.end();
             };
 
@@ -147,6 +161,30 @@ test('VectorTileSource', (t) => {
     testScheme('xyz', 'http://example.com/10/5/5.png');
     testScheme('tms', 'http://example.com/10/5/1018.png');
 
+    t.test('transforms tile urls before requesting', (t) => {
+        window.server.respondWith('/source.json', JSON.stringify(require('../../fixtures/source')));
+
+        const source = createSource({ url: "/source.json" });
+        const transformSpy = t.spy(source.map, '_transformRequest');
+        source.on('data', (e) => {
+            if (e.sourceDataType === 'metadata') {
+                const tile = {
+                    coord: new TileCoord(10, 5, 5, 0),
+                    state: 'loading',
+                    loadVectorData: function () {},
+                    setExpiryData: function() {}
+                };
+                source.loadTile(tile, () => {});
+                t.ok(transformSpy.calledOnce);
+                t.equal(transformSpy.getCall(0).args[0], 'http://example.com/10/5/5.png');
+                t.equal(transformSpy.getCall(0).args[1], 'Tile');
+                t.end();
+            }
+        });
+
+        window.server.respond();
+    });
+
     t.test('reloads a loading tile properly', (t) => {
         const source = createSource({
             tiles: ["http://example.com/{z}/{x}/{y}.png"]
diff --git a/test/unit/source/vector_tile_worker_source.test.js b/test/unit/source/vector_tile_worker_source.test.js
index fcbfd5f0462..e08c3dd6307 100644
--- a/test/unit/source/vector_tile_worker_source.test.js
+++ b/test/unit/source/vector_tile_worker_source.test.js
@@ -11,7 +11,7 @@ test('abortTile', (t) => {
         source.loadTile({
             source: 'source',
             uid: 0,
-            url: 'http://localhost:2900/abort'
+            request: { url: 'http://localhost:2900/abort' }
         }, t.fail);
 
         source.abortTile({
diff --git a/test/unit/source/worker.test.js b/test/unit/source/worker.test.js
index e3ebc0015a9..4e418c418b9 100644
--- a/test/unit/source/worker.test.js
+++ b/test/unit/source/worker.test.js
@@ -16,7 +16,7 @@ test('load tile', (t) => {
             type: 'vector',
             source: 'source',
             uid: 0,
-            url: '/error' // Sinon fake server gives 404 responses by default
+            request: { url: '/error' }// Sinon fake server gives 404 responses by default 
         }, (err) => {
             t.ok(err);
             window.restore();
diff --git a/test/unit/style/style.test.js b/test/unit/style/style.test.js
index 6ba2ab95f31..1aa99c0ceaf 100644
--- a/test/unit/style/style.test.js
+++ b/test/unit/style/style.test.js
@@ -40,6 +40,17 @@ function createGeoJSONSource() {
     };
 }
 
+class StubMap extends Evented {
+    constructor() {
+        super();
+        this.transform = new Transform();
+    }
+
+    _transformRequest(url) {
+        return { url };
+    }
+}
+
 test('Style', (t) => {
     t.afterEach((callback) => {
         window.restore();
@@ -106,6 +117,19 @@ test('Style', (t) => {
         window.server.respond();
     });
 
+    t.test('transforms style URL before request', (t) => {
+        window.useFakeXMLHttpRequest();
+        // window.server.respondWith('/style.json', JSON.stringify(require('../../fixtures/style')));
+        const map = new StubMap();
+        const transformSpy = t.spy(map, '_transformRequest');
+        new Style('/style.json', map);
+        // window.server.respond();
+        t.ok(transformSpy.calledOnce);
+        t.equal(transformSpy.getCall(0).args[0], '/style.json');
+        t.equal(transformSpy.getCall(0).args[1], 'Style');
+        t.end();
+    });
+
     t.test('creates sources', (t) => {
         const style = new Style(util.extend(createStyleJSON(), {
             "sources": {
@@ -114,13 +138,31 @@ test('Style', (t) => {
                     "tiles": []
                 }
             }
-        }));
+        }), new StubMap());
         style.on('style.load', () => {
             t.ok(style.sourceCaches['mapbox'] instanceof SourceCache);
             t.end();
         });
     });
 
+    t.test('transforms sprite json and image URLs before request', (t) => {
+        window.useFakeXMLHttpRequest();
+        const map = new StubMap();
+        const transformSpy = t.spy(map, '_transformRequest');
+        const style = new Style(util.extend(createStyleJSON(), {
+            "sprite": "http://example.com/sprites/bright-v8"
+        }), map);
+        style.on('style.load', () => {
+            t.equal(transformSpy.callCount, 2);
+            t.equal(transformSpy.getCall(0).args[0], 'http://example.com/sprites/bright-v8.json');
+            t.equal(transformSpy.getCall(0).args[1], 'SpriteJSON');
+            t.equal(transformSpy.getCall(1).args[0], 'http://example.com/sprites/bright-v8.png');
+            t.equal(transformSpy.getCall(1).args[1], 'SpriteImage');
+            t.end();
+        });
+
+    });
+
     t.test('validates the style by default', (t) => {
         const style = new Style(createStyleJSON({version: 'invalid'}));
 
@@ -171,7 +213,7 @@ test('Style', (t) => {
                 'source': '-source-id-',
                 'source-layer': '-source-layer-'
             }]
-        }));
+        }), new StubMap());
 
         style.on('style.load', () => {
             style.removeSource('-source-id-');
@@ -263,7 +305,7 @@ test('Style#update', (t) => {
             'source-layer': 'source-layer',
             'type': 'fill'
         }]
-    });
+    }, new StubMap());
 
     style.on('error', (error) => { t.error(error); });
 
@@ -298,7 +340,7 @@ test('Style#_resolve', (t) => {
                 "source-layer": "source-layer",
                 "type": "fill"
             }]
-        });
+        }, new StubMap());
 
         style.on('error', (error) => { t.error(error); });
 
@@ -326,7 +368,7 @@ test('Style#_resolve', (t) => {
                 "type": "fill",
                 "layout": {"visibility": "none"}
             }]
-        });
+        }, new StubMap());
 
         style.on('error', (event) => { t.error(event.error); });
 
@@ -383,7 +425,7 @@ test('Style#setState', (t) => {
             type: 'raster',
             url: '/tilejson.json'
         };
-        const style = new Style(initial);
+        const style = new Style(initial, new StubMap());
         style.on('style.load', () => {
             t.stub(style, 'removeSource').callsFake(() => t.fail('removeSource called'));
             t.stub(style, 'addSource').callsFake(() => t.fail('addSource called'));
@@ -419,7 +461,7 @@ test('Style#setState', (t) => {
 
 test('Style#addSource', (t) => {
     t.test('throw before loaded', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             source = createSource();
         t.throws(() => {
             style.addSource('source-id', source);
@@ -430,7 +472,7 @@ test('Style#addSource', (t) => {
     });
 
     t.test('throw if missing source type', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             source = createSource();
 
         delete source.type;
@@ -444,7 +486,7 @@ test('Style#addSource', (t) => {
     });
 
     t.test('fires "data" event', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             source = createSource();
         style.once('data', t.end);
         style.on('style.load', () => {
@@ -454,7 +496,7 @@ test('Style#addSource', (t) => {
     });
 
     t.test('throws on duplicates', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             source = createSource();
         style.on('style.load', () => {
             style.addSource('source-id', source);
@@ -466,7 +508,7 @@ test('Style#addSource', (t) => {
     });
 
     t.test('emits on invalid source', (t) => {
-        const style = new Style(createStyleJSON());
+        const style = new Style(createStyleJSON(), new StubMap());
         style.on('style.load', () => {
             style.on('error', () => {
                 t.notOk(style.sourceCaches['source-id']);
@@ -488,7 +530,7 @@ test('Style#addSource', (t) => {
                 id: 'background',
                 type: 'background'
             }]
-        }));
+        }), new StubMap());
         const source = createSource();
 
         style.on('style.load', () => {
@@ -523,7 +565,7 @@ test('Style#removeSource', (t) => {
                     "tiles": []
                 }
             }
-        }));
+        }), new StubMap());
         t.throws(() => {
             style.removeSource('source-id');
         }, Error, /load/i);
@@ -533,7 +575,7 @@ test('Style#removeSource', (t) => {
     });
 
     t.test('fires "data" event', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             source = createSource();
         style.once('data', t.end);
         style.on('style.load', () => {
@@ -546,7 +588,7 @@ test('Style#removeSource', (t) => {
     t.test('clears tiles', (t) => {
         const style = new Style(createStyleJSON({
             sources: {'source-id': createGeoJSONSource()}
-        }));
+        }), new StubMap());
 
         style.on('style.load', () => {
             const sourceCache = style.sourceCaches['source-id'];
@@ -560,7 +602,7 @@ test('Style#removeSource', (t) => {
     t.test('emits errors for an invalid style', (t) => {
         const stylesheet = createStyleJSON();
         stylesheet.version =  'INVALID';
-        const style = new Style(stylesheet);
+        const style = new Style(stylesheet, new StubMap());
         style.on('error', (e) => {
             t.deepEqual(e.error.message, 'version: expected one of [8], INVALID found');
             t.end();
@@ -568,7 +610,7 @@ test('Style#removeSource', (t) => {
     });
 
     t.test('throws on non-existence', (t) => {
-        const style = new Style(createStyleJSON());
+        const style = new Style(createStyleJSON(), new StubMap());
         style.on('style.load', () => {
             t.throws(() => {
                 style.removeSource('source-id');
@@ -578,7 +620,7 @@ test('Style#removeSource', (t) => {
     });
 
     t.test('tears down source event forwarding', (t) => {
-        const style = new Style(createStyleJSON());
+        const style = new Style(createStyleJSON(), new StubMap());
         let source = createSource();
 
         style.on('style.load', () => {
@@ -604,7 +646,7 @@ test('Style#removeSource', (t) => {
 
 test('Style#addLayer', (t) => {
     t.test('throw before loaded', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             layer = {id: 'background', type: 'background'};
         t.throws(() => {
             style.addLayer(layer);
@@ -615,7 +657,7 @@ test('Style#addLayer', (t) => {
     });
 
     t.test('sets up layer event forwarding', (t) => {
-        const style = new Style(createStyleJSON());
+        const style = new Style(createStyleJSON(), new StubMap());
 
         style.on('error', (e) => {
             t.deepEqual(e.layer, {id: 'background'});
@@ -638,7 +680,7 @@ test('Style#addLayer', (t) => {
                 // At least one source must be added to trigger the load event
                 dummy: { type: "vector", tiles: [] }
             }
-        }));
+        }), new StubMap());
 
         style.on('style.load', () => {
             const source = createSource();
@@ -665,7 +707,7 @@ test('Style#addLayer', (t) => {
     });
 
     t.test('emits error on invalid layer', (t) => {
-        const style = new Style(createStyleJSON());
+        const style = new Style(createStyleJSON(), new StubMap());
         style.on('style.load', () => {
             style.on('error', () => {
                 t.notOk(style.getLayer('background'));
@@ -689,7 +731,7 @@ test('Style#addLayer', (t) => {
                     "tiles": []
                 }
             }
-        }));
+        }), new StubMap());
         const layer = {
             "id": "symbol",
             "type": "symbol",
@@ -722,7 +764,7 @@ test('Style#addLayer', (t) => {
                 "source-layer": "boxmap",
                 "filter": ["==", "id", 0]
             }]
-        }));
+        }), new StubMap());
 
         const layer = {
             "id": "my-layer",
@@ -758,7 +800,7 @@ test('Style#addLayer', (t) => {
                 "source-layer": "boxmap",
                 "filter": ["==", "id", 0]
             }]
-        }));
+        }), new StubMap());
 
         const layer = {
             "id": "my-layer",
@@ -779,7 +821,7 @@ test('Style#addLayer', (t) => {
     });
 
     t.test('fires "data" event', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             layer = {id: 'background', type: 'background'};
 
         style.once('data', t.end);
@@ -791,7 +833,7 @@ test('Style#addLayer', (t) => {
     });
 
     t.test('emits error on duplicates', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             layer = {id: 'background', type: 'background'};
 
         style.on('error', (e) => {
@@ -816,7 +858,7 @@ test('Style#addLayer', (t) => {
                     id: 'b',
                     type: 'background'
                 }]
-            })),
+            }), new StubMap()),
             layer = {id: 'c', type: 'background'};
 
         style.on('style.load', () => {
@@ -835,7 +877,7 @@ test('Style#addLayer', (t) => {
                     id: 'b',
                     type: 'background'
                 }]
-            })),
+            }), new StubMap()),
             layer = {id: 'c', type: 'background'};
 
         style.on('style.load', () => {
@@ -853,7 +895,7 @@ test('Style#addLayer', (t) => {
                     data: { type: 'FeatureCollection', features: [] }
                 }
             }
-        }));
+        }), new StubMap());
 
         const layer = {
             id: 'dummy',
@@ -879,7 +921,7 @@ test('Style#removeLayer', (t) => {
     t.test('throw before loaded', (t) => {
         const style = new Style(createStyleJSON({
             "layers": [{id: 'background', type: 'background'}]
-        }));
+        }), new StubMap());
         t.throws(() => {
             style.removeLayer('background');
         }, Error, /load/i);
@@ -889,7 +931,7 @@ test('Style#removeLayer', (t) => {
     });
 
     t.test('fires "data" event', (t) => {
-        const style = new Style(createStyleJSON()),
+        const style = new Style(createStyleJSON(), new StubMap()),
             layer = {id: 'background', type: 'background'};
 
         style.once('data', t.end);
@@ -907,7 +949,7 @@ test('Style#removeLayer', (t) => {
                 id: 'background',
                 type: 'background'
             }]
-        }));
+        }), new StubMap());
 
         style.on('error', () => {
             t.fail();
@@ -926,7 +968,7 @@ test('Style#removeLayer', (t) => {
     });
 
     t.test('fires an error on non-existence', (t) => {
-        const style = new Style(createStyleJSON());
+        const style = new Style(createStyleJSON(), new StubMap());
 
         style.on('style.load', () => {
             style.on('error', ({ error }) => {
@@ -1344,7 +1386,7 @@ test('Style#queryRenderedFeatures', (t) => {
                 "something": "else"
             }
         }]
-    });
+    }, new StubMap());
 
     style.on('style.load', () => {
         style._applyClasses([]);
diff --git a/test/unit/symbol/glyph_source.test.js b/test/unit/symbol/glyph_source.test.js
index bed1485dfc0..93b3a9aeb06 100644
--- a/test/unit/symbol/glyph_source.test.js
+++ b/test/unit/symbol/glyph_source.test.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const test = require('mapbox-gl-js-test').test;
+const ajax = require('../../../src/util/ajax');
 const GlyphSource = require('../../../src/symbol/glyph_source');
 const fs = require('fs');
 
@@ -11,7 +12,7 @@ const mockTinySDF = {
 
 function createSource(t, localIdeographFontFamily) {
     const aPBF = fs.readFileSync('./test/fixtures/0-255.pbf');
-    const source = new GlyphSource("https://localhost/fonts/v1{fontstack}/{range}.pbf", localIdeographFontFamily);
+    const source = new GlyphSource("https://localhost/fonts/v1/{fontstack}/{range}.pbf", localIdeographFontFamily);
     t.stub(source, 'createTinySDF').returns(mockTinySDF);
     // It would be better to mock with FakeXMLHttpRequest, but the binary encoding
     // doesn't survive the mocking
@@ -34,6 +35,18 @@ test('GlyphSource', (t) => {
         });
     });
 
+    t.test('transforms glyph URL before request', (t) => {
+        t.stub(ajax, 'getArrayBuffer').callsFake((url, cb) => cb());
+        const transformSpy = t.stub().callsFake((url) => { return { url }; });
+        const source = new GlyphSource("https://localhost/fonts/v1/{fontstack}/{range}.pbf", false, transformSpy);
+
+        source.loadPBF("https://localhost/fonts/v1/Arial Unicode MS/0-255.pbf", () => {
+            t.ok(transformSpy.calledOnce);
+            t.equal(transformSpy.getCall(0).args[0], "https://localhost/fonts/v1/Arial Unicode MS/0-255.pbf");
+            t.end();
+        });
+    });
+
     t.test('requests remote CJK PBF', (t) => {
         const source = createSource(t);
         source.getSimpleGlyphs("Arial Unicode MS", [0x5e73], 0, (err, glyphs, fontName) => {
diff --git a/test/unit/util/ajax.test.js b/test/unit/util/ajax.test.js
index f2cb8ee5707..1a322a329fa 100644
--- a/test/unit/util/ajax.test.js
+++ b/test/unit/util/ajax.test.js
@@ -19,7 +19,7 @@ test('ajax', (t) => {
         window.server.respondWith(request => {
             request.respond(200, {'Content-Type': 'image/png'}, '');
         });
-        ajax.getArrayBuffer('', (error) => {
+        ajax.getArrayBuffer({ url:'' }, (error) => {
             t.pass('called getArrayBuffer');
             t.ok(error, 'should error when the status is 200 without content.');
             t.end();
@@ -31,7 +31,7 @@ test('ajax', (t) => {
         window.server.respondWith(request => {
             request.respond(404);
         });
-        ajax.getArrayBuffer('', (error) => {
+        ajax.getArrayBuffer({ url:'' }, (error) => {
             t.equal(error.status, 404);
             t.end();
         });
@@ -42,7 +42,7 @@ test('ajax', (t) => {
         window.server.respondWith(request => {
             request.respond(200, {'Content-Type': 'application/json'}, '{"foo": "bar"}');
         });
-        ajax.getJSON('', (error, body) => {
+        ajax.getJSON({ url:'' }, (error, body) => {
             t.error(error);
             t.deepEqual(body, {foo: 'bar'});
             t.end();
@@ -54,7 +54,7 @@ test('ajax', (t) => {
         window.server.respondWith(request => {
             request.respond(200, {'Content-Type': 'application/json'}, 'how do i even');
         });
-        ajax.getJSON('', (error) => {
+        ajax.getJSON({ url:'' }, (error) => {
             t.ok(error);
             t.end();
         });
@@ -65,7 +65,7 @@ test('ajax', (t) => {
         window.server.respondWith(request => {
             request.respond(404);
         });
-        ajax.getJSON('', (error) => {
+        ajax.getJSON({ url:'' }, (error) => {
             t.equal(error.status, 404);
             t.end();
         });