diff --git a/src/Umbraco.Tests/Services/ContentTypeServiceTests.cs b/src/Umbraco.Tests/Services/ContentTypeServiceTests.cs
index 5898c27853..7e25ffb6ab 100644
--- a/src/Umbraco.Tests/Services/ContentTypeServiceTests.cs
+++ b/src/Umbraco.Tests/Services/ContentTypeServiceTests.cs
@@ -464,6 +464,91 @@ namespace Umbraco.Tests.Services
             Assert.AreNotEqual(clonedContentType.PropertyGroups.First(x => x.Name.StartsWith("Content")).Id, originalContentType.PropertyGroups.First(x => x.Name.StartsWith("Content")).Id);
         }
 
+        [Test]
+        public void Cannot_Add_Duplicate_PropertyType_Alias_To__Referenced_Composition()
+        {
+            //Related the second issue in screencast from this post http://issues.umbraco.org/issue/U4-5986
+
+            // Arrange
+            var service = ServiceContext.ContentTypeService;
+
+            var parent = MockedContentTypes.CreateSimpleContentType();
+            service.Save(parent);
+            var child = MockedContentTypes.CreateSimpleContentType("simpleChildPage", "Simple Child Page", parent, true);
+            service.Save(child);
+            var composition = MockedContentTypes.CreateMetaContentType();
+            service.Save(composition);
+
+            //Adding Meta-composition to child doc type
+            child.AddContentType(composition);
+            service.Save(child);
+
+            // Act
+            var duplicatePropertyType = new PropertyType(Constants.PropertyEditors.TextboxAlias, DataTypeDatabaseType.Ntext)
+            {
+                Alias = "title", Name = "Title", Description = "", HelpText = "", Mandatory = false, SortOrder = 1, DataTypeDefinitionId = -88
+            };
+            var added = composition.AddPropertyType(duplicatePropertyType, "Meta");
+            service.Save(composition);
+
+            // Assert
+            Assert.That(added, Is.True);
+            Assert.DoesNotThrow(() => service.GetContentType("simpleChildPage"));
+        }
+
+        [Test]
+        public void Can_Rename_PropertyGroup_With_Inherited_PropertyGroups()
+        {
+            //Related the first issue in screencast from this post http://issues.umbraco.org/issue/U4-5986
+            
+            // Arrange
+            var service = ServiceContext.ContentTypeService;
+
+            var page = MockedContentTypes.CreateSimpleContentType("page", "Page", null, false, "Content_");
+            service.Save(page);
+            var contentPage = MockedContentTypes.CreateSimpleContentType("contentPage", "Content Page", page, true);
+            service.Save(contentPage);
+            var composition = MockedContentTypes.CreateMetaContentType();
+            composition.AddPropertyGroup("Content");
+            service.Save(composition);
+            //Adding Meta-composition to child doc type
+            contentPage.AddContentType(composition);
+            service.Save(contentPage);
+
+            // Act
+            var propertyTypeOne = new PropertyType(Constants.PropertyEditors.TextboxAlias, DataTypeDatabaseType.Ntext)
+            {
+                Alias = "testTextbox", Name = "Test Textbox", Description = "", HelpText = "", Mandatory = false, SortOrder = 1, DataTypeDefinitionId = -88
+            };
+            var firstOneAdded = contentPage.AddPropertyType(propertyTypeOne, "Content_");
+            var propertyTypeTwo = new PropertyType(Constants.PropertyEditors.TextboxAlias, DataTypeDatabaseType.Ntext)
+            {
+                Alias = "anotherTextbox", Name = "Another Test Textbox", Description = "", HelpText = "", Mandatory = false, SortOrder = 1, DataTypeDefinitionId = -88
+            };
+            var secondOneAdded = contentPage.AddPropertyType(propertyTypeTwo, "Content");
+            service.Save(contentPage);
+
+            Assert.That(page.PropertyGroups.Contains("Content_"), Is.True);
+            var propertyGroup = page.PropertyGroups["Content_"];
+            page.PropertyGroups.Add(new PropertyGroup{ Id = propertyGroup.Id, Name = "ContentTab", SortOrder = 0});
+            service.Save(page);
+
+            // Assert
+            Assert.That(firstOneAdded, Is.True);
+            Assert.That(secondOneAdded, Is.True);
+
+            var contentType = service.GetContentType("contentPage");
+            Assert.That(contentType, Is.Not.Null);
+
+            var compositionPropertyGroups = contentType.CompositionPropertyGroups;
+            Assert.That(compositionPropertyGroups.Count(x => x.Name.Equals("Content_")), Is.EqualTo(0));
+
+            var propertyTypeCount = contentType.PropertyTypes.Count();
+            var compPropertyTypeCount = contentType.CompositionPropertyTypes.Count();
+            Assert.That(propertyTypeCount, Is.EqualTo(5));
+            Assert.That(compPropertyTypeCount, Is.EqualTo(10));
+        }
+
         private ContentType CreateComponent()
         {
             var component = new ContentType(-1)
diff --git a/src/Umbraco.Tests/TestHelpers/Entities/MockedContentTypes.cs b/src/Umbraco.Tests/TestHelpers/Entities/MockedContentTypes.cs
index 812495d3da..c2ecc1e3e2 100644
--- a/src/Umbraco.Tests/TestHelpers/Entities/MockedContentTypes.cs
+++ b/src/Umbraco.Tests/TestHelpers/Entities/MockedContentTypes.cs
@@ -92,9 +92,9 @@ namespace Umbraco.Tests.TestHelpers.Entities
             return contentType;
         }
 
-		public static ContentType CreateSimpleContentType(string alias, string name, IContentType parent = null, bool randomizeAliases = false)
+        public static ContentType CreateSimpleContentType(string alias, string name, IContentType parent = null, bool randomizeAliases = false, string propertyGroupName = "Content")
 		{
-			var contentType = parent == null ? new ContentType(-1) : new ContentType(parent);
+			var contentType = parent == null ? new ContentType(-1) : new ContentType(parent, alias);
 
 			contentType.Alias = alias;
 			contentType.Name = name;
@@ -110,7 +110,7 @@ namespace Umbraco.Tests.TestHelpers.Entities
             contentCollection.Add(new PropertyType(Constants.PropertyEditors.TinyMCEAlias, DataTypeDatabaseType.Ntext) { Alias = RandomAlias("bodyText", randomizeAliases), Name = "Body Text", Description = "", HelpText = "", Mandatory = false, SortOrder = 2, DataTypeDefinitionId = -87 });
             contentCollection.Add(new PropertyType(Constants.PropertyEditors.TextboxAlias, DataTypeDatabaseType.Ntext) { Alias = RandomAlias("author", randomizeAliases) , Name = "Author", Description = "Name of the author", HelpText = "", Mandatory = false, SortOrder = 3, DataTypeDefinitionId = -88 });
 
-			contentType.PropertyGroups.Add(new PropertyGroup(contentCollection) { Name = "Content", SortOrder = 1 });
+            contentType.PropertyGroups.Add(new PropertyGroup(contentCollection) { Name = propertyGroupName, SortOrder = 1 });
 
             //ensure that nothing is marked as dirty
             contentType.ResetDirtyProperties(false);
@@ -167,6 +167,27 @@ namespace Umbraco.Tests.TestHelpers.Entities
             return contentType;
         }
 
+        public static ContentType CreateSimpleContentType(string alias, string name, PropertyTypeCollection collection, string propertyGroupName, IContentType parent = null)
+        {
+            var contentType = parent == null ? new ContentType(-1) : new ContentType(parent, alias);
+
+            contentType.Alias = alias;
+            contentType.Name = name;
+            contentType.Description = "ContentType used for simple text pages";
+            contentType.Icon = ".sprTreeDoc3";
+            contentType.Thumbnail = "doc2.png";
+            contentType.SortOrder = 1;
+            contentType.CreatorId = 0;
+            contentType.Trashed = false;
+
+            contentType.PropertyGroups.Add(new PropertyGroup(collection) { Name = propertyGroupName, SortOrder = 1 });
+
+            //ensure that nothing is marked as dirty
+            contentType.ResetDirtyProperties(false);
+
+            return contentType;
+        }
+
         public static ContentType CreateSimpleContentType(string alias, string name, PropertyTypeCollection groupedCollection, PropertyTypeCollection nonGroupedCollection)
         {
             var contentType = CreateSimpleContentType(alias, name, groupedCollection);