diff --git a/modules/swagger-codegen/src/main/resources/objc/Model.xcdatamodel.mustache b/modules/swagger-codegen/src/main/resources/objc/Model.xcdatamodel.mustache
index 90dcd63e3d9..dddac8fd743 100644
--- a/modules/swagger-codegen/src/main/resources/objc/Model.xcdatamodel.mustache
+++ b/modules/swagger-codegen/src/main/resources/objc/Model.xcdatamodel.mustache
@@ -2,8 +2,8 @@
 <model userDefinedModelVersionIdentifier="" type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="9525" systemVersion="15D21" minimumToolsVersion="Xcode 7.0">
 
     {{#models}}{{#model}}<entity name="{{{classname}}}ManagedObject" representedClassName="{{{classname}}}ManagedObject" syncable="YES">
-{{#isArrayModel}}       <relationship name="entries" optional="YES" toMany="YES" deletionRule="Cascade" destinationEntity="{{{arrayModelType}}}ManagedObject" syncable="YES"/>
-{{/isArrayModel}}{{^isArrayModel}}{{#vars}}{{#complexType}}       <relationship name="{{name}}" {{^required}}optional="YES"{{/required}} {{#isListContainer}}toMany="YES"{{/isListContainer}}{{^isListContainer}}maxCount="1"{{/isListContainer}} deletionRule="Cascade" destinationEntity="{{{complexType}}}ManagedObject" syncable="YES"/>{{/complexType}}{{^complexType}}       <attribute name="{{name}}" {{^required}}optional="YES"{{/required}} attributeType="{{#isString}}String{{/isString}}{{#isInteger}}Integer 16{{/isInteger}}{{#isLong}}Double{{/isLong}}{{#isDouble}}Double{{/isDouble}}{{#isFloat}}Float{{/isFloat}}{{#isByteArray}}Binary{{/isByteArray}}{{#isBinary}}Binary{{/isBinary}}{{#isListContainer}}Transformable{{/isListContainer}}{{#isMapContainer}}Transformable{{/isMapContainer}}{{#isBoolean}}Boolean{{/isBoolean}}{{#isDate}}Date{{/isDate}}{{#isDateTime}}Date{{/isDateTime}}" syncable="YES"/>{{/complexType}}{{#vendorExtensions.x-is-unique}}
+{{#isArrayModel}}        <relationship name="entries" optional="YES" toMany="YES" deletionRule="Cascade" destinationEntity="{{{arrayModelType}}}ManagedObject" syncable="YES"/>
+{{/isArrayModel}}{{^isArrayModel}}{{#vars}}{{#complexType}}        <relationship name="{{name}}" {{^required}}optional="YES"{{/required}} {{#isListContainer}}toMany="YES" ordered="YES"{{/isListContainer}}{{^isListContainer}}maxCount="1"{{/isListContainer}} deletionRule="Cascade" destinationEntity="{{{complexType}}}ManagedObject" syncable="YES"/>{{/complexType}}{{^complexType}}        <attribute name="{{name}}" {{^required}}optional="YES"{{/required}} attributeType="{{#isString}}String{{/isString}}{{#isInteger}}Integer 16{{/isInteger}}{{#isLong}}Double{{/isLong}}{{#isDouble}}Double{{/isDouble}}{{#isFloat}}Float{{/isFloat}}{{#isByteArray}}Binary{{/isByteArray}}{{#isBinary}}Binary{{/isBinary}}{{#isListContainer}}Transformable{{/isListContainer}}{{#isMapContainer}}Transformable{{/isMapContainer}}{{#isBoolean}}Boolean{{/isBoolean}}{{#isDate}}Date{{/isDate}}{{#isDateTime}}Date{{/isDateTime}}" syncable="YES"/>{{/complexType}}{{#vendorExtensions.x-is-unique}}
        <uniquenessConstraints><uniquenessConstraint><constraint value="{{name}}"/></uniquenessConstraint></uniquenessConstraints>{{/vendorExtensions.x-is-unique}}
 {{/vars}}
 {{/isArrayModel}}
diff --git a/modules/swagger-codegen/src/main/resources/objc/NSManagedObject-header.mustache b/modules/swagger-codegen/src/main/resources/objc/NSManagedObject-header.mustache
index 53bc9172472..fcf71612c93 100644
--- a/modules/swagger-codegen/src/main/resources/objc/NSManagedObject-header.mustache
+++ b/modules/swagger-codegen/src/main/resources/objc/NSManagedObject-header.mustache
@@ -14,7 +14,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface {{classname}}ManagedObject : NSManagedObject
 
-@property (nullable, nonatomic, retain) NSSet<{{{arrayModelType}}}ManagedObject*>* entries;
+@property (nullable, nonatomic, retain) NSOrderedSet<{{{arrayModelType}}}ManagedObject*>* entries;
 
 {{/isArrayModel}}{{^isArrayModel}}
 @interface {{classname}}ManagedObject : {{#parent}}{{{parent}}}ManagedObject{{/parent}}{{^parent}}NSManagedObject{{/parent}}
@@ -22,7 +22,7 @@ NS_ASSUME_NONNULL_BEGIN
 {{#vars}}
 {{#description}}/* {{{description}}} {{^required}}[optional]{{/required}}
  */{{/description}}
-@property (nullable, nonatomic, retain) {{^complexType}}{{{ datatype }}}{{/complexType}}{{#complexType}}{{#isListContainer}}NSSet<{{{complexType}}}ManagedObject*>*{{/isListContainer}}{{^isListContainer}}{{#isMapContainer}}{{{ datatype }}}{{/isMapContainer}}{{^isMapContainer}}{{{complexType}}}ManagedObject*{{/isMapContainer}}{{/isListContainer}}{{/complexType}} {{name}};
+@property (nullable, nonatomic, retain) {{^complexType}}{{{ datatype }}}{{/complexType}}{{#complexType}}{{#isListContainer}}NSOrderedSet<{{{complexType}}}ManagedObject*>*{{/isListContainer}}{{^isListContainer}}{{#isMapContainer}}{{{ datatype }}}{{/isMapContainer}}{{^isMapContainer}}{{{complexType}}}ManagedObject*{{/isMapContainer}}{{/isListContainer}}{{/complexType}} {{name}};
 {{/vars}}
 {{/isArrayModel}}
 @end
@@ -31,14 +31,14 @@ NS_ASSUME_NONNULL_BEGIN
 {{#isArrayModel}}
 - (void)addEntriesObject:({{arrayModelType}}ManagedObject *)value;
 - (void)removeEntriesObject:({{arrayModelType}}ManagedObject *)value;
-- (void)addEntries:(NSSet<{{{arrayModelType}}}ManagedObject*> *)values;
-- (void)removeEntries:(NSSet<{{{arrayModelType}}}ManagedObject*> *)values;
+- (void)addEntries:(NSOrderedSet<{{{arrayModelType}}}ManagedObject*> *)values;
+- (void)removeEntries:(NSOrderedSet<{{{arrayModelType}}}ManagedObject*> *)values;
 {{/isArrayModel}}
 {{^isArrayModel}}
 {{#vars}}{{#isListContainer}}{{#complexType}}- (void)add{{vendorExtensions.x-uppercaseName}}Object:({{complexType}}ManagedObject *)value;
 - (void)remove{{vendorExtensions.x-uppercaseName}}Object:({{complexType}}ManagedObject *)value;
-- (void)add{{vendorExtensions.x-uppercaseName}}:(NSSet<{{{complexType}}}ManagedObject*> *)values;
-- (void)remove{{vendorExtensions.x-uppercaseName}}:(NSSet<{{{complexType}}}ManagedObject*> *)values;
+- (void)add{{vendorExtensions.x-uppercaseName}}:(NSOrderedSet<{{{complexType}}}ManagedObject*> *)values;
+- (void)remove{{vendorExtensions.x-uppercaseName}}:(NSOrderedSet<{{{complexType}}}ManagedObject*> *)values;
 {{/complexType}}{{/isListContainer}}{{/vars}}
 {{/isArrayModel}}
 @end
diff --git a/modules/swagger-codegen/src/main/resources/objc/NSManagedObjectBuilder-body.mustache b/modules/swagger-codegen/src/main/resources/objc/NSManagedObjectBuilder-body.mustache
index b6b69135286..8bff47a1288 100644
--- a/modules/swagger-codegen/src/main/resources/objc/NSManagedObjectBuilder-body.mustache
+++ b/modules/swagger-codegen/src/main/resources/objc/NSManagedObjectBuilder-body.mustache
@@ -35,7 +35,7 @@
         return;
     }
 {{#vars}}{{^complexType}}    managedObject.{{name}} = [object.{{name}} copy];{{/complexType}}{{#complexType}}{{#isListContainer}}    if(object.{{name}}) {
-        NSMutableSet * convertedObjs = [NSMutableSet set];
+        NSMutableOrderedSet * convertedObjs = [NSMutableOrderedSet orderedSet];
         for (id innerObject in object.{{name}}) {
             id convertedObj = [self.{{name}}Builder {{complexType}}ManagedObjectFrom{{complexType}}:innerObject context:managedObject.managedObjectContext];
             [convertedObjs addObject:convertedObj];
@@ -47,7 +47,7 @@
     } else {
         [self.{{name}}Builder update{{complexType}}ManagedObject:managedObject.{{name}} with{{complexType}}:object.{{name}}];
     }{{/isMapContainer}}{{#isMapContainer}}managedObject.{{name}} = [object.{{name}} copy];{{/isMapContainer}}{{/isListContainer}}{{/complexType}}
-{{/vars}}{{#isArrayModel}}    NSMutableSet * convertedObjs = [NSMutableSet set];
+{{/vars}}{{#isArrayModel}}    NSMutableOrderedSet * convertedObjs = [NSMutableOrderedSet orderedSet];
     for (id innerObject in object) {
         id convertedObj = [self.entriesBuilder {{arrayModelType}}ManagedObjectFrom{{arrayModelType}}:innerObject context:managedObject.managedObjectContext];
         [convertedObjs addObject:convertedObj];
diff --git a/samples/client/petstore/objc/core-data/README.md b/samples/client/petstore/objc/core-data/README.md
index eb7dc0b57a8..eac7e114ddb 100644
--- a/samples/client/petstore/objc/core-data/README.md
+++ b/samples/client/petstore/objc/core-data/README.md
@@ -6,7 +6,7 @@ This ObjC package is automatically generated by the [Swagger Codegen](https://gi
 
 - API version: 1.0.0
 - Package version: 
-- Build date: 2016-08-23T10:56:27.632+02:00
+- Build date: 2016-09-06T10:33:51.799+02:00
 - Build package: class io.swagger.codegen.languages.ObjcClientCodegen
 
 ## Requirements
diff --git a/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGModel.xcdatamodeld/SWGModel.xcdatamodel/contents b/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGModel.xcdatamodeld/SWGModel.xcdatamodel/contents
index d6c893f1d25..4ec7a3b456b 100644
--- a/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGModel.xcdatamodeld/SWGModel.xcdatamodel/contents
+++ b/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGModel.xcdatamodeld/SWGModel.xcdatamodel/contents
@@ -2,38 +2,38 @@
 <model userDefinedModelVersionIdentifier="" type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="9525" systemVersion="15D21" minimumToolsVersion="Xcode 7.0">
 
     <entity name="SWGCategoryManagedObject" representedClassName="SWGCategoryManagedObject" syncable="YES">
-       <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
-       <attribute name="name" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
+        <attribute name="name" optional="YES" attributeType="String" syncable="YES"/>
     </entity>
     <entity name="SWGOrderManagedObject" representedClassName="SWGOrderManagedObject" syncable="YES">
-       <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
-       <attribute name="petId" optional="YES" attributeType="Double" syncable="YES"/>
-       <attribute name="quantity" optional="YES" attributeType="Integer 16" syncable="YES"/>
-       <attribute name="shipDate" optional="YES" attributeType="Date" syncable="YES"/>
-       <attribute name="status" optional="YES" attributeType="String" syncable="YES"/>
-       <attribute name="complete" optional="YES" attributeType="Boolean" syncable="YES"/>
+        <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
+        <attribute name="petId" optional="YES" attributeType="Double" syncable="YES"/>
+        <attribute name="quantity" optional="YES" attributeType="Integer 16" syncable="YES"/>
+        <attribute name="shipDate" optional="YES" attributeType="Date" syncable="YES"/>
+        <attribute name="status" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="complete" optional="YES" attributeType="Boolean" syncable="YES"/>
     </entity>
     <entity name="SWGPetManagedObject" representedClassName="SWGPetManagedObject" syncable="YES">
-       <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
-       <relationship name="category" optional="YES" maxCount="1" deletionRule="Cascade" destinationEntity="SWGCategoryManagedObject" syncable="YES"/>
-       <attribute name="name"  attributeType="String" syncable="YES"/>
-       <attribute name="photoUrls"  attributeType="Transformable" syncable="YES"/>
-       <relationship name="tags" optional="YES" toMany="YES" deletionRule="Cascade" destinationEntity="SWGTagManagedObject" syncable="YES"/>
-       <attribute name="status" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
+        <relationship name="category" optional="YES" maxCount="1" deletionRule="Cascade" destinationEntity="SWGCategoryManagedObject" syncable="YES"/>
+        <attribute name="name"  attributeType="String" syncable="YES"/>
+        <attribute name="photoUrls"  attributeType="Transformable" syncable="YES"/>
+        <relationship name="tags" optional="YES" toMany="YES" ordered="YES" deletionRule="Cascade" destinationEntity="SWGTagManagedObject" syncable="YES"/>
+        <attribute name="status" optional="YES" attributeType="String" syncable="YES"/>
     </entity>
     <entity name="SWGTagManagedObject" representedClassName="SWGTagManagedObject" syncable="YES">
-       <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
-       <attribute name="name" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
+        <attribute name="name" optional="YES" attributeType="String" syncable="YES"/>
     </entity>
     <entity name="SWGUserManagedObject" representedClassName="SWGUserManagedObject" syncable="YES">
-       <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
-       <attribute name="username" optional="YES" attributeType="String" syncable="YES"/>
-       <attribute name="firstName" optional="YES" attributeType="String" syncable="YES"/>
-       <attribute name="lastName" optional="YES" attributeType="String" syncable="YES"/>
-       <attribute name="email" optional="YES" attributeType="String" syncable="YES"/>
-       <attribute name="password" optional="YES" attributeType="String" syncable="YES"/>
-       <attribute name="phone" optional="YES" attributeType="String" syncable="YES"/>
-       <attribute name="userStatus" optional="YES" attributeType="Integer 16" syncable="YES"/>
+        <attribute name="_id" optional="YES" attributeType="Double" syncable="YES"/>
+        <attribute name="username" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="firstName" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="lastName" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="email" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="password" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="phone" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="userStatus" optional="YES" attributeType="Integer 16" syncable="YES"/>
     </entity>
     
 </model>
\ No newline at end of file
diff --git a/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGPetManagedObject.h b/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGPetManagedObject.h
index e24f3a58975..99ab2c3c9e2 100644
--- a/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGPetManagedObject.h
+++ b/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGPetManagedObject.h
@@ -42,7 +42,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (nullable, nonatomic, retain) NSArray<NSString*>* photoUrls;
 
-@property (nullable, nonatomic, retain) NSSet<SWGTagManagedObject*>* tags;
+@property (nullable, nonatomic, retain) NSOrderedSet<SWGTagManagedObject*>* tags;
 /* pet status in the store [optional]
  */
 @property (nullable, nonatomic, retain) NSString* status;
@@ -51,8 +51,8 @@ NS_ASSUME_NONNULL_BEGIN
 @interface SWGPetManagedObject (GeneratedAccessors)
 - (void)addTagsObject:(SWGTagManagedObject *)value;
 - (void)removeTagsObject:(SWGTagManagedObject *)value;
-- (void)addTags:(NSSet<SWGTagManagedObject*> *)values;
-- (void)removeTags:(NSSet<SWGTagManagedObject*> *)values;
+- (void)addTags:(NSOrderedSet<SWGTagManagedObject*> *)values;
+- (void)removeTags:(NSOrderedSet<SWGTagManagedObject*> *)values;
 
 @end
 
diff --git a/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGPetManagedObjectBuilder.m b/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGPetManagedObjectBuilder.m
index 49b9139c810..13b4d0e6acf 100644
--- a/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGPetManagedObjectBuilder.m
+++ b/samples/client/petstore/objc/core-data/SwaggerClient/Model/SWGPetManagedObjectBuilder.m
@@ -44,7 +44,7 @@
     managedObject.name = [object.name copy];
     managedObject.photoUrls = [object.photoUrls copy];
     if(object.tags) {
-        NSMutableSet * convertedObjs = [NSMutableSet set];
+        NSMutableOrderedSet * convertedObjs = [NSMutableOrderedSet orderedSet];
         for (id innerObject in object.tags) {
             id convertedObj = [self.tagsBuilder SWGTagManagedObjectFromSWGTag:innerObject context:managedObject.managedObjectContext];
             [convertedObjs addObject:convertedObj];
diff --git a/samples/client/petstore/objc/default/README.md b/samples/client/petstore/objc/default/README.md
index dc09ad22254..f9e83a324e0 100644
--- a/samples/client/petstore/objc/default/README.md
+++ b/samples/client/petstore/objc/default/README.md
@@ -6,7 +6,7 @@ This ObjC package is automatically generated by the [Swagger Codegen](https://gi
 
 - API version: 1.0.0
 - Package version: 
-- Build date: 2016-08-23T10:56:26.470+02:00
+- Build date: 2016-09-06T10:33:50.612+02:00
 - Build package: class io.swagger.codegen.languages.ObjcClientCodegen
 
 ## Requirements