diff --git a/lib/utils.js b/lib/utils.js
index 85fa657593..c637648442 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -13,6 +13,7 @@ var debug = require('debug')('mocha:watch');
 var fs = require('fs');
 var glob = require('glob');
 var path = require('path');
+var util = require('util');
 var join = path.join;
 var he = require('he');
 var errors = require('./errors');
@@ -531,7 +532,7 @@ exports.lookupFiles = function lookupFiles(filepath, extensions, recursive) {
       files = glob.sync(filepath);
       if (!files.length) {
         throw createNoFilesMatchPatternError(
-          'Cannot find any files matching pattern "' + filepath + '"',
+          'Cannot find any files matching pattern ' + exports.dQuote(filepath),
           filepath
         );
       }
@@ -565,7 +566,11 @@ exports.lookupFiles = function lookupFiles(filepath, extensions, recursive) {
     }
     if (!extensions) {
       throw createMissingArgumentError(
-        'Argument "extensions" required when argument "filepath" is a directory',
+        util.format(
+          'Argument %s required when argument %s is a directory',
+          exports.sQuote('extensions'),
+          exports.sQuote('filepath')
+        ),
         'extensions',
         'array'
       );
@@ -763,7 +768,7 @@ exports.sQuote = function(str) {
  *
  * @description
  * Provides a simple means of markup for quoting text to be used in output.
- * Use this to quote names of datatypes, classes, and strings.
+ * Use this to quote names of datatypes, classes, pathnames, and strings.
  *
  * <samp>argument 'value' must be "string" or "number"</samp>
  *