diff --git a/packages/ember-data/lib/serializers/json_serializer.js b/packages/ember-data/lib/serializers/json_serializer.js
index d17f9dfd4e5..611666310e5 100644
--- a/packages/ember-data/lib/serializers/json_serializer.js
+++ b/packages/ember-data/lib/serializers/json_serializer.js
@@ -391,9 +391,9 @@ DS.JSONSerializer = Ember.Object.extend({
 
     var relationshipType = DS.RelationshipChange.determineRelationshipType(record.constructor, relationship);
 
-    if (relationshipType === 'manyToNone' || relationshipType === 'manyToMany') {
+    if (relationshipType === 'manyToNone' || relationshipType === 'manyToOne' || relationshipType === 'manyToMany') {
       json[key] = get(record, key).mapBy('id');
-      // TODO support for polymorphic manyToNone and manyToMany relationships
+      // TODO support for polymorphic manyToNone, manyToOne and manyToMany relationships
     }
   },
 
diff --git a/packages/ember-data/tests/integration/serializers/json_serializer_test.js b/packages/ember-data/tests/integration/serializers/json_serializer_test.js
index ce78ec5025b..d64e88bf3d9 100644
--- a/packages/ember-data/tests/integration/serializers/json_serializer_test.js
+++ b/packages/ember-data/tests/integration/serializers/json_serializer_test.js
@@ -112,3 +112,26 @@ test("serializePolymorphicType", function() {
     postTYPE: "post"
   });
 });
+
+
+test("serializeHasMany", function() {
+  Post.reopen({
+    comments: DS.hasMany('comment')
+  });
+
+  post = env.store.createRecord(Post, { title: "Rails is omakase", id: "1"});
+  comment = env.store.createRecord(Comment, { body: "Omakase is delicious", post: post});
+  post.get('comments').addObject(comment);
+
+  deepEqual(post.get('comments.content'),
+    [comment]
+  );
+
+  var json = {};
+
+  env.serializer.serializeHasMany(post, json, {key: "comments", options: {}});
+
+  deepEqual(json, {
+    comments: [comment.get('id')]
+  });
+});
diff --git a/packages/ember-data/tests/integration/serializers/rest_serializer_test.js b/packages/ember-data/tests/integration/serializers/rest_serializer_test.js
index 27fcf55a20c..c4616476fc9 100644
--- a/packages/ember-data/tests/integration/serializers/rest_serializer_test.js
+++ b/packages/ember-data/tests/integration/serializers/rest_serializer_test.js
@@ -264,7 +264,8 @@ test("serializeIntoHash", function() {
 
   deepEqual(json, {
     homePlanet: {
-      name: "Umber"
+      name: "Umber",
+      superVillains: []
     }
   });
 });
@@ -278,7 +279,8 @@ test("serializeIntoHash with decamelized typeKey", function() {
 
   deepEqual(json, {
     homePlanet: {
-      name: "Umber"
+      name: "Umber",
+      superVillains: []
     }
   });
 });