diff --git a/packages/ember-model/lib/belongs_to.js b/packages/ember-model/lib/belongs_to.js
index c84b8ec..b371707 100644
--- a/packages/ember-model/lib/belongs_to.js
+++ b/packages/ember-model/lib/belongs_to.js
@@ -1,5 +1,5 @@
 var get = Ember.get,
-    set = Ember.set;
+  set = Ember.set;
 
 function storeFor(record) {
   if (record.container) {
@@ -9,20 +9,45 @@ function storeFor(record) {
   return null;
 }
 
+function isValidType(type, record) {
+  var hasContainer = record.container;
+  var isObject = (typeof type  === "object" || typeof type  === "function");
+
+  if (hasContainer && isObject) {
+    return false;
+  }
+
+  if (!isObject) {
+    if (hasContainer && Ember.get(Ember.lookup, type)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 function getType(record) {
   var type = this.type;
 
-  if (typeof this.type === "string" && this.type) {
-    type = Ember.get(Ember.lookup, this.type);
+  if (record) {
+    Ember.assert("Models created from store must define relationships with strings not objects. Using convention 'post' not 'App.Post'", isValidType(this.type, record));
+  }
+  if (typeof this.type  === "object" || typeof this.type  === "function") {
+    return this.type;
+  }
+
+  this.type = get(Ember.lookup, type);
 
-    if (!type) {
-      var store = storeFor(record);
-      type = store.modelFor(this.type);
-      type.reopenClass({ adapter: store.adapterFor(this.type) });
-    }
+  if (this.type) {
+    return this.type;
   }
 
-  return type;
+  else {
+    var store = storeFor(record);
+    this.type = store.modelFor(type);
+    this.type.reopenClass({ adapter: store.adapterFor(type) });
+    return this.type;
+  }
 }
 
 Ember.belongsTo = function(type, options) {
diff --git a/packages/ember-model/lib/has_many.js b/packages/ember-model/lib/has_many.js
index c4b7444..1dd414d 100644
--- a/packages/ember-model/lib/has_many.js
+++ b/packages/ember-model/lib/has_many.js
@@ -1,19 +1,43 @@
 var get = Ember.get;
 
+function isValidType(type, record) {
+  var hasContainer = record.container;
+  var isObject = (typeof type === "object" || typeof type === "function");
+
+  if (hasContainer && isObject) {
+    return false;
+  }
+
+  if (!isObject) {
+    if (hasContainer && get(Ember.lookup, type)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 function getType(record) {
   var type = this.type;
 
-  if (typeof this.type === "string" && this.type) {
-    this.type = Ember.get(Ember.lookup, this.type);
+  Ember.assert("Models created from store must define relationships with strings not objects. Using convention 'post' not 'App.Post'", isValidType(this.type, record));
 
-    if (!this.type) {
-      var store = record.container.lookup('store:main');
-      this.type = store.modelFor(type);
-      this.type.reopenClass({ adapter: store.adapterFor(type) });
-    }
+  if (typeof this.type  === "object" || typeof this.type  === "function") {
+    return this.type;
+  }
+
+  this.type = Ember.get(Ember.lookup, type);
+
+  if (this.type) {
+    return this.type;
   }
 
-  return this.type;
+  else {
+    var store = record.container.lookup('store:main');
+    this.type = store.modelFor(type);
+    this.type.reopenClass({ adapter: store.adapterFor(type) });
+    return this.type;
+  }
 }
 
 Ember.hasMany = function(type, options) {
diff --git a/packages/ember-model/lib/store.js b/packages/ember-model/lib/store.js
index 3828518..cf096c9 100644
--- a/packages/ember-model/lib/store.js
+++ b/packages/ember-model/lib/store.js
@@ -2,7 +2,11 @@ Ember.Model.Store = Ember.Object.extend({
   container: null,
 
   modelFor: function(type) {
-    return this.container.lookupFactory('model:'+type);
+    if (typeof type === 'string') {
+      return this.container.lookupFactory('model:'+type);
+    } else {
+      return type;
+    }
   },
 
   adapterFor: function(type) {
diff --git a/packages/ember-model/tests/belongs_to_test.js b/packages/ember-model/tests/belongs_to_test.js
index cb2ea9b..1673754 100644
--- a/packages/ember-model/tests/belongs_to_test.js
+++ b/packages/ember-model/tests/belongs_to_test.js
@@ -725,4 +725,27 @@ test("non embedded belongsTo should return a record with a container", function(
     start();
     ok(article.get('container'));
   });
+});
+
+test("model cannot be specified as an object if container exists", function() {
+  var App;
+  Ember.run(function() {
+    App = Ember.Application.create({});
+  });
+  App.Article  = Ember.Model.extend({
+    id: Ember.attr(String)
+  });
+  App.Comment = Ember.Model.extend({
+    article: Ember.belongsTo(App.Article, { key: 'article', embedded: true })
+  });
+
+  var comment = App.Comment.create({container: App.__container__});
+  Ember.run(comment, comment.load, 1, { article: { id: 'a' } });
+
+  expectAssertion(function() {
+      comment.get('article');
+    },
+    /Models created from store must define relationships with strings not objects. Using convention 'post' not 'App.Post'/);
+
+  Ember.run(App, 'destroy');
 });
\ No newline at end of file
diff --git a/packages/ember-model/tests/has_many_test.js b/packages/ember-model/tests/has_many_test.js
index 78f8145..30d267c 100644
--- a/packages/ember-model/tests/has_many_test.js
+++ b/packages/ember-model/tests/has_many_test.js
@@ -95,10 +95,10 @@ test("model can be specified with a string to a resolved path", function() {
   });
   App.Comment = Ember.Model.extend({
     id: Ember.attr(String),
-    subComments: Ember.hasMany('subcomment', { key: 'subcomments', embedded: true })
+    subComments: Ember.hasMany('subcomment', {embedded: true })
   });
   App.Article = Ember.Model.extend({
-    comments: Ember.hasMany('comment', { key: 'comments', embedded: true })
+    comments: Ember.hasMany('comment', {embedded: true })
   });
 
   var article = App.Article.create({container: App.__container__});
@@ -275,4 +275,29 @@ test("key defaults to model's property key", function() {
   Ember.run(article, article.load, 1, { comments: Ember.A(['a'] )});
 
   deepEqual(article.toJSON(), { comments: ['a'] });
+});
+
+test("model cannot be specified as an object if container exists", function() {
+  var App;
+  Ember.run(function() {
+    App = Ember.Application.create({});
+  });
+
+  App.Comment = Ember.Model.extend({
+    id: Ember.attr()
+  });
+  App.Article = Ember.Model.extend({
+    comments: Ember.hasMany(App.Comment, {embedded: true })
+  });
+
+  var article = App.Article.create({container: App.__container__});
+
+  Ember.run(article, article.load, 1, {comments: Ember.A([{id: 'a'}, {id: 'b'}])});
+
+  expectAssertion(function() {
+      article.get('comments');
+    },
+    /Models created from store must define relationships with strings not objects. Using convention 'post' not 'App.Post'/);
+
+  Ember.run(App, 'destroy');
 });
\ No newline at end of file