diff --git a/dist/amd/factory-guy.js b/dist/amd/factory-guy.js
index 85ed876b..d167ddc9 100644
--- a/dist/amd/factory-guy.js
+++ b/dist/amd/factory-guy.js
@@ -441,12 +441,45 @@ var FactoryGuy = {
    @returns {Object} json fixture data
    */
   pushFixture: function (modelClass, fixture) {
+    var index;
     if (!modelClass.FIXTURES) {
       modelClass.FIXTURES = [];
     }
-    modelClass.FIXTURES.push(fixture);
+
+    index = this.indexOfFixture(modelClass.FIXTURES, fixture);
+
+    if (index > -1) {
+      modelClass.FIXTURES[index] = fixture;
+    } else {
+      modelClass.FIXTURES.push(fixture);
+    }
+
     return fixture;
   },
+
+  /**
+   Used in compliment with pushFixture in order to
+   ensure we don't push duplicate fixtures
+
+   @private
+   @param {Array} fixtures
+   @param {String|Integer} id of fixture to find
+   @returns {Object} fixture
+   */
+  indexOfFixture: function(fixtures, fixture) {
+    var index = -1,
+        id = fixture.id + '';
+    Ember.A(fixtures).find(function(r, i) {
+      if ('' + Ember.get(r, 'id') === id) {
+        index = i;
+        return true;
+      } else {
+        return false;
+      }
+    });
+    return index;
+  },
+
   /**
    Clears all model definitions
   */
diff --git a/dist/ember-data-factory-guy.js b/dist/ember-data-factory-guy.js
index a2559111..f06d3287 100644
--- a/dist/ember-data-factory-guy.js
+++ b/dist/ember-data-factory-guy.js
@@ -436,12 +436,45 @@ var FactoryGuy = {
    @returns {Object} json fixture data
    */
   pushFixture: function (modelClass, fixture) {
+    var index;
     if (!modelClass.FIXTURES) {
       modelClass.FIXTURES = [];
     }
-    modelClass.FIXTURES.push(fixture);
+
+    index = this.indexOfFixture(modelClass.FIXTURES, fixture);
+
+    if (index > -1) {
+      modelClass.FIXTURES[index] = fixture;
+    } else {
+      modelClass.FIXTURES.push(fixture);
+    }
+
     return fixture;
   },
+
+  /**
+   Used in compliment with pushFixture in order to
+   ensure we don't push duplicate fixtures
+
+   @private
+   @param {Array} fixtures
+   @param {String|Integer} id of fixture to find
+   @returns {Object} fixture
+   */
+  indexOfFixture: function(fixtures, fixture) {
+    var index = -1,
+        id = fixture.id + '';
+    Ember.A(fixtures).find(function(r, i) {
+      if ('' + Ember.get(r, 'id') === id) {
+        index = i;
+        return true;
+      } else {
+        return false;
+      }
+    });
+    return index;
+  },
+
   /**
    Clears all model definitions
   */
diff --git a/dist/ember-data-factory-guy.min.js b/dist/ember-data-factory-guy.min.js
index 99dd51b9..0f149f7b 100644
--- a/dist/ember-data-factory-guy.min.js
+++ b/dist/ember-data-factory-guy.min.js
@@ -1 +1 @@
-var Sequence=function(fn){var index=1;this.next=function(){return fn.call(this,index++)};this.reset=function(){index=1}};var MissingSequenceError=function(message){this.toString=function(){return message}};if(FactoryGuy!==undefined){FactoryGuy.sequence=Sequence;FactoryGuy.missingSequenceError=MissingSequenceError}var ModelDefinition=function(model,config){var sequences={};var traits={};var defaultAttributes={};var namedModels={};var modelId=1;var sequenceName=null;this.model=model;this.matchesName=function(name){return model==name||namedModels[name]};this.nextId=function(){return modelId++};this.generate=function(name,sequenceFn){if(sequenceFn){if(!sequences[name]){sequences[name]=new Sequence(sequenceFn)}}var sequence=sequences[name];if(!sequence){throw new MissingSequenceError("Can not find that sequence named ["+sequenceName+"] in '"+model+"' definition")}return sequence.next()};this.build=function(name,opts,traitArgs){var traitsObj={};traitArgs.forEach(function(trait){$.extend(traitsObj,traits[trait])});var modelAttributes=namedModels[name]||{};var fixture=$.extend({},defaultAttributes,modelAttributes,traitsObj,opts);for(var attribute in fixture){if(Ember.typeOf(fixture[attribute])=="function"){fixture[attribute]=fixture[attribute].call(this,fixture)}else if(Ember.typeOf(fixture[attribute])=="object"){fixture[attribute]=FactoryGuy.build(attribute,fixture[attribute])}}if(!fixture.id){fixture.id=this.nextId()}return fixture};this.buildList=function(name,number,traits,opts){var arr=[];for(var i=0;i<number;i++){arr.push(this.build(name,opts,traits))}return arr};this.reset=function(){modelId=1;for(var name in sequences){sequences[name].reset()}};var parseDefault=function(object){if(!object){return}defaultAttributes=object};var parseTraits=function(object){if(!object){return}traits=object};var parseSequences=function(object){if(!object){return}for(sequenceName in object){var sequenceFn=object[sequenceName];if(Ember.typeOf(sequenceFn)!="function"){throw new Error("Problem with ["+sequenceName+"] sequence definition. Sequences must be functions")}object[sequenceName]=new Sequence(sequenceFn)}sequences=object};var parseConfig=function(config){parseSequences(config.sequences);delete config.sequences;parseTraits(config.traits);delete config.traits;parseDefault(config.default);delete config.default;namedModels=config};parseConfig(config)};if(FactoryGuy!==undefined){FactoryGuy.modelDefiniton=ModelDefinition}var FactoryGuy={modelDefinitions:{},define:function(model,config){if(this.modelDefinitions[model]){this.modelDefinitions[model].merge(config)}else{this.modelDefinitions[model]=new ModelDefinition(model,config)}},generate:function(nameOrFunction){var sortaRandomName=Math.floor((1+Math.random())*65536).toString(16)+Date.now();return function(){if(Em.typeOf(nameOrFunction)=="function"){return this.generate(sortaRandomName,nameOrFunction)}else{return this.generate(nameOrFunction)}}},belongsTo:function(fixtureName,opts){return function(){return FactoryGuy.build(fixtureName,opts)}},association:function(fixtureName,opts){console.log("DEPRECATION Warning: use FactoryGuy.belongsTo instead");return this.belongsTo(fixtureName,opts)},hasMany:function(fixtureName,number,opts){return function(){return FactoryGuy.buildList(fixtureName,number,opts)}},lookupModelForFixtureName:function(name){var definition=this.lookupDefinitionForFixtureName(name);if(definition){return definition.model}},lookupDefinitionForFixtureName:function(name){for(var model in this.modelDefinitions){var definition=this.modelDefinitions[model];if(definition.matchesName(name)){return definition}}},build:function(){var args=Array.prototype.slice.call(arguments);var opts={};var name=args.shift();if(!name){throw new Error("Build needs a factory name to build")}if(Ember.typeOf(args[args.length-1])=="object"){opts=args.pop()}var traits=args;var definition=this.lookupDefinitionForFixtureName(name);if(!definition){throw new Error("Can't find that factory named ["+name+"]")}return definition.build(name,opts,traits)},buildList:function(){var args=Array.prototype.slice.call(arguments);var name=args.shift();var number=args.shift();if(!name||!number){throw new Error("buildList needs a name and a number ( at least ) to build with")}var opts={};if(Ember.typeOf(args[args.length-1])=="object"){opts=args.pop()}var traits=args;var definition=this.lookupDefinitionForFixtureName(name);if(!definition){throw new Error("Can't find that factory named ["+name+"]")}return definition.buildList(name,number,traits,opts)},resetModels:function(store){for(var model in this.modelDefinitions){var definition=this.modelDefinitions[model];definition.reset();try{var modelType=store.modelFor(definition.model);if(store.usingFixtureAdapter()){modelType.FIXTURES=[]}store.unloadAll(modelType)}catch(e){console.log("resetModels",e)}}},pushFixture:function(modelClass,fixture){if(!modelClass.FIXTURES){modelClass.FIXTURES=[]}modelClass.FIXTURES.push(fixture);return fixture},clear:function(opts){if(!opts){this.modelDefinitions={}}}};(function(){DS.Store.reopen({usingFixtureAdapter:function(){var adapter=this.adapterFor("application");return adapter instanceof DS.FixtureAdapter},makeFixture:function(){var store=this;var fixture=FactoryGuy.build.apply(FactoryGuy,arguments);var name=arguments[0];var modelName=FactoryGuy.lookupModelForFixtureName(name);var modelType=store.modelFor(modelName);if(this.usingFixtureAdapter()){this.setAssociationsForFixtureAdapter(modelType,modelName,fixture);return FactoryGuy.pushFixture(modelType,fixture)}else{return store.makeModel(modelType,fixture)}},makeModel:function(modelType,fixture){var store=this,modelName=store.modelFor(modelType).typeKey,model;Em.run(function(){store.findEmbeddedAssociationsForRESTAdapter(modelType,fixture);if(fixture.type){modelName=fixture.type.underscore();modelType=store.modelFor(modelName)}model=store.push(modelName,fixture);store.setAssociationsForRESTAdapter(modelType,modelName,model)});return model},makeList:function(){var arr=[];var number=arguments[1];for(var i=0;i<number;i++){arr.push(this.makeFixture.apply(this,arguments))}return arr},setAssociationsForFixtureAdapter:function(modelType,modelName,fixture){var self=this;var adapter=this.adapterFor("application");Ember.get(modelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind=="hasMany"){var hasManyRelation=fixture[relationship.key];if(hasManyRelation){$.each(fixture[relationship.key],function(index,object){var id=object;if(Ember.typeOf(object)=="object"){id=object.id;hasManyRelation[index]=id}var hasManyfixtures=adapter.fixturesForType(relationship.type);var fixture=adapter.findFixtureById(hasManyfixtures,id);fixture[modelName]=fixture.id})}}if(relationship.kind=="belongsTo"){var belongsToRecord=fixture[relationship.key];if(belongsToRecord){if(typeof belongsToRecord=="object"){FactoryGuy.pushFixture(relationship.type,belongsToRecord);fixture[relationship.key]=belongsToRecord.id}var hasManyName=self.findHasManyRelationshipNameForFixtureAdapter(relationship.type,relationship.parentType);var belongsToFixtures=adapter.fixturesForType(relationship.type);var belongsTofixture=adapter.findFixtureById(belongsToFixtures,fixture[relationship.key]);if(!belongsTofixture[hasManyName]){belongsTofixture[hasManyName]=[]}belongsTofixture[hasManyName].push(fixture.id)}}})},findEmbeddedAssociationsForRESTAdapter:function(modelType,fixture){var store=this;Ember.get(modelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind=="belongsTo"){var belongsToRecord=fixture[relationship.key];if(Ember.typeOf(belongsToRecord)=="object"){store.findEmbeddedAssociationsForRESTAdapter(relationship.type,belongsToRecord);belongsToRecord=store.push(relationship.type,belongsToRecord);fixture[relationship.key]=belongsToRecord}}if(relationship.kind=="hasMany"){var hasManyRecords=fixture[relationship.key];if(Ember.typeOf(hasManyRecords)=="array"){if(Ember.typeOf(hasManyRecords[0])=="object"){var records=Em.A();hasManyRecords.map(function(object){store.findEmbeddedAssociationsForRESTAdapter(relationship.type,object);var record=store.push(relationship.type,object);records.push(record);return record});fixture[relationship.key]=records}}}})},setAssociationsForRESTAdapter:function(modelType,modelName,model){var self=this;Ember.get(modelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind=="hasMany"){var children=model.get(name)||[];children.forEach(function(child){var belongsToName=self.findRelationshipName("belongsTo",child.constructor,model);if(belongsToName){child.set(belongsToName,model)}})}})},findRelationshipName:function(kind,belongToModelType,childModel){var relationshipName;Ember.get(belongToModelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind==kind&&childModel instanceof relationship.type){relationshipName=relationship.key}});return relationshipName},findHasManyRelationshipNameForFixtureAdapter:function(belongToModelType,childModelType){var relationshipName;Ember.get(belongToModelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind=="hasMany"&&childModelType==relationship.type){relationshipName=relationship.key}});return relationshipName},pushPayload:function(type,payload){if(this.usingFixtureAdapter()){var model=this.modelFor(type);FactoryGuy.pushFixture(model,payload)}else{this._super(type,payload)}}})})();var FactoryGuyTestMixin=Em.Mixin.create({setup:function(app){this.set("container",app.__container__);return this},useFixtureAdapter:function(app){app.ApplicationAdapter=DS.FixtureAdapter;this.getStore().adapterFor("application").simulateRemoteResponse=false},usingActiveModelSerializer:function(type){var store=this.getStore();var modelType=store.modelFor(type);var serializer=store.serializerFor(modelType.typeKey);return serializer instanceof DS.ActiveModelSerializer},find:function(type,id){return this.getStore().find(type,id)},make:function(){var store=this.getStore();return store.makeFixture.apply(store,arguments)},getStore:function(){return this.get("container").lookup("store:main")},pushPayload:function(type,hash){return this.getStore().pushPayload(type,hash)},pushRecord:function(type,hash){return this.getStore().push(type,hash)},stubEndpointForHttpRequest:function(url,json,options){options=options||{};var request={url:url,dataType:"json",responseText:json,type:options.type||"GET",status:options.status||200};if(options.data){request.data=options.data}$.mockjax(request)},buildURL:function(typeName,id){var type=this.getStore().modelFor(typeName);return this.getStore().adapterFor(type).buildURL(type.typeKey,id)},handleFindMany:function(){var store=this.getStore();store.makeList.apply(store,arguments);var name=arguments[0];var modelName=FactoryGuy.lookupModelForFixtureName(name);var responseJson={};responseJson[modelName]=[];var url=this.buildURL(modelName);this.stubEndpointForHttpRequest(url,responseJson,{type:"GET"})},handleCreate:function(modelName,options){var opts=options===undefined?{}:options;var succeed=opts.succeed===undefined?true:opts.succeed;var match=opts.match||{};var returnArgs=opts.returns||{};var url=this.buildURL(modelName);var definition=FactoryGuy.modelDefinitions[modelName];var httpOptions={type:"POST"};if(opts.match){var expectedRequest={};var record=this.getStore().createRecord(modelName,match);expectedRequest[modelName]=record.serialize();httpOptions.data=JSON.stringify(expectedRequest)}var modelType=this.getStore().modelFor(modelName);var responseJson={};if(succeed){if(options){responseJson[modelName]=$.extend({id:definition.nextId()},match,returnArgs);Ember.get(modelType,"relationshipsByName").forEach(function(relationship){if(relationship.kind=="belongsTo"){delete responseJson[modelName][relationship.key]}})}}else{httpOptions.status=500}this.stubEndpointForHttpRequest(url,responseJson,httpOptions)},handleUpdate:function(type,id,succeed){succeed=succeed===undefined?true:succeed;this.stubEndpointForHttpRequest(this.buildURL(type,id),{},{type:"PUT",status:succeed?200:500})},handleDelete:function(type,id,succeed){succeed=succeed===undefined?true:succeed;this.stubEndpointForHttpRequest(this.buildURL(type,id),{},{type:"DELETE",status:succeed?200:500})},teardown:function(){FactoryGuy.resetModels(this.getStore());$.mockjax.clear()}});if(FactoryGuy!==undefined){FactoryGuy.testMixin=FactoryGuyTestMixin}
\ No newline at end of file
+var Sequence=function(fn){var index=1;this.next=function(){return fn.call(this,index++)};this.reset=function(){index=1}};var MissingSequenceError=function(message){this.toString=function(){return message}};if(FactoryGuy!==undefined){FactoryGuy.sequence=Sequence;FactoryGuy.missingSequenceError=MissingSequenceError}var ModelDefinition=function(model,config){var sequences={};var traits={};var defaultAttributes={};var namedModels={};var modelId=1;var sequenceName=null;this.model=model;this.matchesName=function(name){return model==name||namedModels[name]};this.nextId=function(){return modelId++};this.generate=function(name,sequenceFn){if(sequenceFn){if(!sequences[name]){sequences[name]=new Sequence(sequenceFn)}}var sequence=sequences[name];if(!sequence){throw new MissingSequenceError("Can not find that sequence named ["+sequenceName+"] in '"+model+"' definition")}return sequence.next()};this.build=function(name,opts,traitArgs){var traitsObj={};traitArgs.forEach(function(trait){$.extend(traitsObj,traits[trait])});var modelAttributes=namedModels[name]||{};var fixture=$.extend({},defaultAttributes,modelAttributes,traitsObj,opts);for(var attribute in fixture){if(Ember.typeOf(fixture[attribute])=="function"){fixture[attribute]=fixture[attribute].call(this,fixture)}else if(Ember.typeOf(fixture[attribute])=="object"){fixture[attribute]=FactoryGuy.build(attribute,fixture[attribute])}}if(!fixture.id){fixture.id=this.nextId()}return fixture};this.buildList=function(name,number,traits,opts){var arr=[];for(var i=0;i<number;i++){arr.push(this.build(name,opts,traits))}return arr};this.reset=function(){modelId=1;for(var name in sequences){sequences[name].reset()}};var parseDefault=function(object){if(!object){return}defaultAttributes=object};var parseTraits=function(object){if(!object){return}traits=object};var parseSequences=function(object){if(!object){return}for(sequenceName in object){var sequenceFn=object[sequenceName];if(Ember.typeOf(sequenceFn)!="function"){throw new Error("Problem with ["+sequenceName+"] sequence definition. Sequences must be functions")}object[sequenceName]=new Sequence(sequenceFn)}sequences=object};var parseConfig=function(config){parseSequences(config.sequences);delete config.sequences;parseTraits(config.traits);delete config.traits;parseDefault(config.default);delete config.default;namedModels=config};parseConfig(config)};if(FactoryGuy!==undefined){FactoryGuy.modelDefiniton=ModelDefinition}var FactoryGuy={modelDefinitions:{},define:function(model,config){if(this.modelDefinitions[model]){this.modelDefinitions[model].merge(config)}else{this.modelDefinitions[model]=new ModelDefinition(model,config)}},generate:function(nameOrFunction){var sortaRandomName=Math.floor((1+Math.random())*65536).toString(16)+Date.now();return function(){if(Em.typeOf(nameOrFunction)=="function"){return this.generate(sortaRandomName,nameOrFunction)}else{return this.generate(nameOrFunction)}}},belongsTo:function(fixtureName,opts){return function(){return FactoryGuy.build(fixtureName,opts)}},association:function(fixtureName,opts){console.log("DEPRECATION Warning: use FactoryGuy.belongsTo instead");return this.belongsTo(fixtureName,opts)},hasMany:function(fixtureName,number,opts){return function(){return FactoryGuy.buildList(fixtureName,number,opts)}},lookupModelForFixtureName:function(name){var definition=this.lookupDefinitionForFixtureName(name);if(definition){return definition.model}},lookupDefinitionForFixtureName:function(name){for(var model in this.modelDefinitions){var definition=this.modelDefinitions[model];if(definition.matchesName(name)){return definition}}},build:function(){var args=Array.prototype.slice.call(arguments);var opts={};var name=args.shift();if(!name){throw new Error("Build needs a factory name to build")}if(Ember.typeOf(args[args.length-1])=="object"){opts=args.pop()}var traits=args;var definition=this.lookupDefinitionForFixtureName(name);if(!definition){throw new Error("Can't find that factory named ["+name+"]")}return definition.build(name,opts,traits)},buildList:function(){var args=Array.prototype.slice.call(arguments);var name=args.shift();var number=args.shift();if(!name||!number){throw new Error("buildList needs a name and a number ( at least ) to build with")}var opts={};if(Ember.typeOf(args[args.length-1])=="object"){opts=args.pop()}var traits=args;var definition=this.lookupDefinitionForFixtureName(name);if(!definition){throw new Error("Can't find that factory named ["+name+"]")}return definition.buildList(name,number,traits,opts)},resetModels:function(store){for(var model in this.modelDefinitions){var definition=this.modelDefinitions[model];definition.reset();try{var modelType=store.modelFor(definition.model);if(store.usingFixtureAdapter()){modelType.FIXTURES=[]}store.unloadAll(modelType)}catch(e){console.log("resetModels",e)}}},pushFixture:function(modelClass,fixture){var index;if(!modelClass.FIXTURES){modelClass.FIXTURES=[]}index=this.indexOfFixture(modelClass.FIXTURES,fixture);if(index>-1){modelClass.FIXTURES[index]=fixture}else{modelClass.FIXTURES.push(fixture)}return fixture},indexOfFixture:function(fixtures,fixture){var index=-1,id=fixture.id+"";Ember.A(fixtures).find(function(r,i){if(""+Ember.get(r,"id")===id){index=i;return true}else{return false}});return index},clear:function(opts){if(!opts){this.modelDefinitions={}}}};(function(){DS.Store.reopen({usingFixtureAdapter:function(){var adapter=this.adapterFor("application");return adapter instanceof DS.FixtureAdapter},makeFixture:function(){var store=this;var fixture=FactoryGuy.build.apply(FactoryGuy,arguments);var name=arguments[0];var modelName=FactoryGuy.lookupModelForFixtureName(name);var modelType=store.modelFor(modelName);if(this.usingFixtureAdapter()){this.setAssociationsForFixtureAdapter(modelType,modelName,fixture);return FactoryGuy.pushFixture(modelType,fixture)}else{return store.makeModel(modelType,fixture)}},makeModel:function(modelType,fixture){var store=this,modelName=store.modelFor(modelType).typeKey,model;Em.run(function(){store.findEmbeddedAssociationsForRESTAdapter(modelType,fixture);if(fixture.type){modelName=fixture.type.underscore();modelType=store.modelFor(modelName)}model=store.push(modelName,fixture);store.setAssociationsForRESTAdapter(modelType,modelName,model)});return model},makeList:function(){var arr=[];var number=arguments[1];for(var i=0;i<number;i++){arr.push(this.makeFixture.apply(this,arguments))}return arr},setAssociationsForFixtureAdapter:function(modelType,modelName,fixture){var self=this;var adapter=this.adapterFor("application");Ember.get(modelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind=="hasMany"){var hasManyRelation=fixture[relationship.key];if(hasManyRelation){$.each(fixture[relationship.key],function(index,object){var id=object;if(Ember.typeOf(object)=="object"){id=object.id;hasManyRelation[index]=id}var hasManyfixtures=adapter.fixturesForType(relationship.type);var fixture=adapter.findFixtureById(hasManyfixtures,id);fixture[modelName]=fixture.id})}}if(relationship.kind=="belongsTo"){var belongsToRecord=fixture[relationship.key];if(belongsToRecord){if(typeof belongsToRecord=="object"){FactoryGuy.pushFixture(relationship.type,belongsToRecord);fixture[relationship.key]=belongsToRecord.id}var hasManyName=self.findHasManyRelationshipNameForFixtureAdapter(relationship.type,relationship.parentType);var belongsToFixtures=adapter.fixturesForType(relationship.type);var belongsTofixture=adapter.findFixtureById(belongsToFixtures,fixture[relationship.key]);if(!belongsTofixture[hasManyName]){belongsTofixture[hasManyName]=[]}belongsTofixture[hasManyName].push(fixture.id)}}})},findEmbeddedAssociationsForRESTAdapter:function(modelType,fixture){var store=this;Ember.get(modelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind=="belongsTo"){var belongsToRecord=fixture[relationship.key];if(Ember.typeOf(belongsToRecord)=="object"){store.findEmbeddedAssociationsForRESTAdapter(relationship.type,belongsToRecord);belongsToRecord=store.push(relationship.type,belongsToRecord);fixture[relationship.key]=belongsToRecord}}if(relationship.kind=="hasMany"){var hasManyRecords=fixture[relationship.key];if(Ember.typeOf(hasManyRecords)=="array"){if(Ember.typeOf(hasManyRecords[0])=="object"){var records=Em.A();hasManyRecords.map(function(object){store.findEmbeddedAssociationsForRESTAdapter(relationship.type,object);var record=store.push(relationship.type,object);records.push(record);return record});fixture[relationship.key]=records}}}})},setAssociationsForRESTAdapter:function(modelType,modelName,model){var self=this;Ember.get(modelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind=="hasMany"){var children=model.get(name)||[];children.forEach(function(child){var belongsToName=self.findRelationshipName("belongsTo",child.constructor,model);if(belongsToName){child.set(belongsToName,model)}})}})},findRelationshipName:function(kind,belongToModelType,childModel){var relationshipName;Ember.get(belongToModelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind==kind&&childModel instanceof relationship.type){relationshipName=relationship.key}});return relationshipName},findHasManyRelationshipNameForFixtureAdapter:function(belongToModelType,childModelType){var relationshipName;Ember.get(belongToModelType,"relationshipsByName").forEach(function(relationship,name){if(relationship.kind=="hasMany"&&childModelType==relationship.type){relationshipName=relationship.key}});return relationshipName},pushPayload:function(type,payload){if(this.usingFixtureAdapter()){var model=this.modelFor(type);FactoryGuy.pushFixture(model,payload)}else{this._super(type,payload)}}})})();var FactoryGuyTestMixin=Em.Mixin.create({setup:function(app){this.set("container",app.__container__);return this},useFixtureAdapter:function(app){app.ApplicationAdapter=DS.FixtureAdapter;this.getStore().adapterFor("application").simulateRemoteResponse=false},usingActiveModelSerializer:function(type){var store=this.getStore();var modelType=store.modelFor(type);var serializer=store.serializerFor(modelType.typeKey);return serializer instanceof DS.ActiveModelSerializer},find:function(type,id){return this.getStore().find(type,id)},make:function(){var store=this.getStore();return store.makeFixture.apply(store,arguments)},getStore:function(){return this.get("container").lookup("store:main")},pushPayload:function(type,hash){return this.getStore().pushPayload(type,hash)},pushRecord:function(type,hash){return this.getStore().push(type,hash)},stubEndpointForHttpRequest:function(url,json,options){options=options||{};var request={url:url,dataType:"json",responseText:json,type:options.type||"GET",status:options.status||200};if(options.data){request.data=options.data}$.mockjax(request)},buildURL:function(typeName,id){var type=this.getStore().modelFor(typeName);return this.getStore().adapterFor(type).buildURL(type.typeKey,id)},handleFindMany:function(){var store=this.getStore();store.makeList.apply(store,arguments);var name=arguments[0];var modelName=FactoryGuy.lookupModelForFixtureName(name);var responseJson={};responseJson[modelName]=[];var url=this.buildURL(modelName);this.stubEndpointForHttpRequest(url,responseJson,{type:"GET"})},handleCreate:function(modelName,options){var opts=options===undefined?{}:options;var succeed=opts.succeed===undefined?true:opts.succeed;var match=opts.match||{};var returnArgs=opts.returns||{};var url=this.buildURL(modelName);var definition=FactoryGuy.modelDefinitions[modelName];var httpOptions={type:"POST"};if(opts.match){var expectedRequest={};var record=this.getStore().createRecord(modelName,match);expectedRequest[modelName]=record.serialize();httpOptions.data=JSON.stringify(expectedRequest)}var modelType=this.getStore().modelFor(modelName);var responseJson={};if(succeed){if(options){responseJson[modelName]=$.extend({id:definition.nextId()},match,returnArgs);Ember.get(modelType,"relationshipsByName").forEach(function(relationship){if(relationship.kind=="belongsTo"){delete responseJson[modelName][relationship.key]}})}}else{httpOptions.status=500}this.stubEndpointForHttpRequest(url,responseJson,httpOptions)},handleUpdate:function(type,id,succeed){succeed=succeed===undefined?true:succeed;this.stubEndpointForHttpRequest(this.buildURL(type,id),{},{type:"PUT",status:succeed?200:500})},handleDelete:function(type,id,succeed){succeed=succeed===undefined?true:succeed;this.stubEndpointForHttpRequest(this.buildURL(type,id),{},{type:"DELETE",status:succeed?200:500})},teardown:function(){FactoryGuy.resetModels(this.getStore());$.mockjax.clear()}});if(FactoryGuy!==undefined){FactoryGuy.testMixin=FactoryGuyTestMixin}
\ No newline at end of file
diff --git a/src/factory_guy.js b/src/factory_guy.js
index 7d6afb00..4c0bec74 100644
--- a/src/factory_guy.js
+++ b/src/factory_guy.js
@@ -268,12 +268,45 @@ var FactoryGuy = {
    @returns {Object} json fixture data
    */
   pushFixture: function (modelClass, fixture) {
+    var index;
     if (!modelClass.FIXTURES) {
       modelClass.FIXTURES = [];
     }
-    modelClass.FIXTURES.push(fixture);
+
+    index = this.indexOfFixture(modelClass.FIXTURES, fixture);
+
+    if (index > -1) {
+      modelClass.FIXTURES[index] = fixture;
+    } else {
+      modelClass.FIXTURES.push(fixture);
+    }
+
     return fixture;
   },
+
+  /**
+   Used in compliment with pushFixture in order to
+   ensure we don't push duplicate fixtures
+
+   @private
+   @param {Array} fixtures
+   @param {String|Integer} id of fixture to find
+   @returns {Object} fixture
+   */
+  indexOfFixture: function(fixtures, fixture) {
+    var index = -1,
+        id = fixture.id + '';
+    Ember.A(fixtures).find(function(r, i) {
+      if ('' + Ember.get(r, 'id') === id) {
+        index = i;
+        return true;
+      } else {
+        return false;
+      }
+    });
+    return index;
+  },
+
   /**
    Clears all model definitions
   */
@@ -282,4 +315,4 @@ var FactoryGuy = {
       this.modelDefinitions = {};
     }
   }
-};
\ No newline at end of file
+};
diff --git a/tests/factory_guy_test.js b/tests/factory_guy_test.js
index 5f41a627..6fb904af 100644
--- a/tests/factory_guy_test.js
+++ b/tests/factory_guy_test.js
@@ -203,3 +203,26 @@ test("#lookupModelForFixtureName", function() {
   equal(FactoryGuy.lookupModelForFixtureName('fake'), undefined, "return nothing if can't find definition");
 });
 
+asyncTest("#pushFixture", function() {
+  var User = store.modelFor('user'),
+      user = store.makeFixture('user'),
+      duplicateUser = FactoryGuy.build('user', { id: user.id, name: 'monkey' }),
+      differentUser = FactoryGuy.build('user'),
+      usersById = {};
+
+  usersById[duplicateUser.id] = duplicateUser;
+  usersById[differentUser.id] = differentUser;
+
+  FactoryGuy.pushFixture(User, duplicateUser);
+  FactoryGuy.pushFixture(User, differentUser);
+
+  store.find('user').then(function(users) {
+    ok(users.get('length') === 2);
+
+    users.forEach(function(user) {
+      equal(user.get('name'), usersById[user.get('id')].name, "Updates model fixture if duplicate id found");
+    });
+
+    start();
+  });
+});
diff --git a/vendor/assets/javascripts/ember_data_factory_guy.js b/vendor/assets/javascripts/ember_data_factory_guy.js
index 74c80c85..7f20a65f 100644
--- a/vendor/assets/javascripts/ember_data_factory_guy.js
+++ b/vendor/assets/javascripts/ember_data_factory_guy.js
@@ -436,12 +436,45 @@ var FactoryGuy = {
    @returns {Object} json fixture data
    */
   pushFixture: function (modelClass, fixture) {
+    var index;
     if (!modelClass.FIXTURES) {
       modelClass.FIXTURES = [];
     }
-    modelClass.FIXTURES.push(fixture);
+
+    index = this.indexOfFixture(modelClass.FIXTURES, fixture);
+
+    if (index > -1) {
+      modelClass.FIXTURES[index] = fixture;
+    } else {
+      modelClass.FIXTURES.push(fixture);
+    }
+
     return fixture;
   },
+
+  /**
+   Used in compliment with pushFixture in order to
+   ensure we don't push duplicate fixtures
+
+   @private
+   @param {Array} fixtures
+   @param {String|Integer} id of fixture to find
+   @returns {Object} fixture
+   */
+  indexOfFixture: function(fixtures, fixture) {
+    var index = -1,
+        id = fixture.id + '';
+    Ember.A(fixtures).find(function(r, i) {
+      if ('' + Ember.get(r, 'id') === id) {
+        index = i;
+        return true;
+      } else {
+        return false;
+      }
+    });
+    return index;
+  },
+
   /**
    Clears all model definitions
   */
@@ -1023,9 +1056,6 @@ if (FactoryGuy !== undefined) {
 		}
 		// Inspect the data submitted in the request (either POST body or GET query string)
 		if ( handler.data ) {
-//      console.log('request.data', requestSettings.data )
-//      console.log('handler.data', handler.data )
-//      console.log('data equal', isMockDataEqual(handler.data, requestSettings.data) )
 			if ( ! requestSettings.data || !isMockDataEqual(handler.data, requestSettings.data) ) {
 				// They're not identical, do not mock this request
 				return null;