diff --git a/JSONAPI.EntityFramework.Tests/EntityFrameworkMaterializerTests.cs b/JSONAPI.EntityFramework.Tests/EntityFrameworkMaterializerTests.cs
new file mode 100644
index 00000000..01f9e437
--- /dev/null
+++ b/JSONAPI.EntityFramework.Tests/EntityFrameworkMaterializerTests.cs
@@ -0,0 +1,88 @@
+using System;
+using System.Linq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using JSONAPI.EntityFramework.Tests.Models;
+using FluentAssertions;
+using System.Collections.Generic;
+
+namespace JSONAPI.EntityFramework.Tests
+{
+    [TestClass]
+    public class EntityFrameworkMaterializerTests
+    {
+        private class NotAnEntity
+        {
+            public string Id { get; set; }
+            public string Temporary { get; set; }
+        }
+
+        private TestEntities context;
+        private Backlink b1, b2;
+
+        [TestInitialize]
+        public void SetupEntities()
+        {
+            //- See http://stackoverflow.com/a/19130718/489116
+            var instance = System.Data.Entity.SqlServer.SqlProviderServices.Instance;
+            //-
+
+            context = new TestEntities();
+            //JSONAPI.EntityFramework.Json.ContractResolver.ObjectContext = context;
+
+
+            // Clear it out!
+            foreach (Backlink o in context.Backlinks) context.Backlinks.Remove(o);
+            context.SaveChanges();
+
+            b1 = new Backlink
+            {
+                Url = "http://www.google.com/",
+                Snippet = "1 Results"
+            };
+
+            context.SaveChanges();
+        }
+
+        [TestMethod]
+        public void GetKeyNamesStandardIdTest()
+        {
+            // Arrange
+            var materializer = new EntityFrameworkMaterializer(context);
+
+            // Act
+            IEnumerable<string> keyNames = materializer.GetKeyNames(typeof(Post));
+
+            // Assert
+            keyNames.Count().Should().Be(1);
+            keyNames.First().Should().Be("Id");
+        }
+
+        [TestMethod]
+        public void GetKeyNamesNonStandardIdTest()
+        {
+            // Arrange
+            var materializer = new EntityFrameworkMaterializer(context);
+
+            // Act
+            IEnumerable<string> keyNames = materializer.GetKeyNames(typeof(Backlink));
+
+            // Assert
+            keyNames.Count().Should().Be(1);
+            keyNames.First().Should().Be("Url");
+        }
+
+        [TestMethod]
+        [ExpectedException(typeof(System.ArgumentException))]
+        public void GetKeyNamesNotAnEntityTest()
+        {
+            // Arrange
+            var materializer = new EntityFrameworkMaterializer(context);
+
+            // Act
+            IEnumerable<string> keyNames = materializer.GetKeyNames(typeof(NotAnEntity));
+
+            // Assert
+            Assert.Fail("A System.ArgumentException should be thrown, this assertion should be unreachable!");
+        }
+    }
+}
diff --git a/JSONAPI.EntityFramework.Tests/JSONAPI.EntityFramework.Tests.csproj b/JSONAPI.EntityFramework.Tests/JSONAPI.EntityFramework.Tests.csproj
index 791fab24..a8608ba1 100644
--- a/JSONAPI.EntityFramework.Tests/JSONAPI.EntityFramework.Tests.csproj
+++ b/JSONAPI.EntityFramework.Tests/JSONAPI.EntityFramework.Tests.csproj
@@ -90,11 +90,13 @@
   <ItemGroup>
     <Compile Include="ActionFilters\EnumerateQueryableAsyncAttributeTests.cs" />
     <Compile Include="EntityConverterTests.cs" />
+    <Compile Include="EntityFrameworkMaterializerTests.cs" />
     <Compile Include="Helpers\TestDbAsyncEnumerable.cs" />
     <Compile Include="Helpers\WaitsUntilCancellationDbAsyncEnumerator.cs" />
     <Compile Include="Helpers\TestDbAsyncEnumerator.cs" />
     <Compile Include="Helpers\TestDbAsyncQueryProvider.cs" />
     <Compile Include="Models\Author.cs" />
+    <Compile Include="Models\Backlink.cs" />
     <Compile Include="Models\Comment.cs" />
     <Compile Include="Models\TestEntities.cs" />
     <Compile Include="Models\Post.cs" />
diff --git a/JSONAPI.EntityFramework.Tests/Models/Backlink.cs b/JSONAPI.EntityFramework.Tests/Models/Backlink.cs
new file mode 100644
index 00000000..168f19be
--- /dev/null
+++ b/JSONAPI.EntityFramework.Tests/Models/Backlink.cs
@@ -0,0 +1,18 @@
+using JSONAPI.Attributes;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace JSONAPI.EntityFramework.Tests.Models
+{
+    public class Backlink
+    {
+        [UseAsId]
+        [System.ComponentModel.DataAnnotations.Key]
+        public string Url { get; set; }
+
+        public Post Post { get; set; }
+        public string Snippet { get; set; }
+    }
+}
diff --git a/JSONAPI.EntityFramework.Tests/Models/TestEntities.cs b/JSONAPI.EntityFramework.Tests/Models/TestEntities.cs
index cb6a7db9..67b61d3b 100644
--- a/JSONAPI.EntityFramework.Tests/Models/TestEntities.cs
+++ b/JSONAPI.EntityFramework.Tests/Models/TestEntities.cs
@@ -6,6 +6,8 @@
     
     public partial class TestEntities : DbContext
     {
+        private class TestEntitiesInitializer : DropCreateDatabaseIfModelChanges<TestEntities> { }
+
         public TestEntities()
             : base("name=TestEntities")
         {
@@ -13,11 +15,12 @@ public TestEntities()
     
         protected override void OnModelCreating(DbModelBuilder modelBuilder)
         {
-            //throw new UnintentionalCodeFirstException();
+            Database.SetInitializer<TestEntities>(new TestEntitiesInitializer());
         }
     
         public virtual DbSet<Author> Authors { get; set; }
         public virtual DbSet<Post> Posts { get; set; }
         public virtual DbSet<Comment> Comments { get; set; }
+        public virtual DbSet<Backlink> Backlinks { get; set; }
     }
 }
diff --git a/JSONAPI.EntityFramework/EntityFrameworkMaterializer.cs b/JSONAPI.EntityFramework/EntityFrameworkMaterializer.cs
index 635128d2..cca5b1f4 100644
--- a/JSONAPI.EntityFramework/EntityFrameworkMaterializer.cs
+++ b/JSONAPI.EntityFramework/EntityFrameworkMaterializer.cs
@@ -184,25 +184,28 @@ private Type GetSingleType(Type type)
                 return type;
         }
 
-        protected virtual IEnumerable<string> GetKeyNames(Type type)
+        protected internal virtual IEnumerable<string> GetKeyNames(Type type)
         {
-            try
-            {
-                // If this fails, type must not be in the context!!!
-                ObjectContext objectContext = ((IObjectContextAdapter)this.context).ObjectContext;
-                IEnumerable<string> retval = (IEnumerable<string>)objectContext.MetadataWorkspace
-                    .GetType(type.Name, type.Namespace, System.Data.Entity.Core.Metadata.Edm.DataSpace.CSpace)
-                    .MetadataProperties
-                    .Where(mp => mp.Name == "KeyMembers")
-                    .First()
-                    .Value;
-                return retval;
+            ObjectContext objectContext = ((IObjectContextAdapter)this.context).ObjectContext;
+            System.Data.Entity.Core.Metadata.Edm.EdmType meta;
+            try {
+                meta = objectContext.MetadataWorkspace
+                    .GetType(type.Name, type.Namespace, System.Data.Entity.Core.Metadata.Edm.DataSpace.CSpace);
             }
-            catch (Exception e)
+            catch (System.ArgumentException e)
             {
-                // Type is not an entity type in the context. Um...now what? Either override this in a subclass, or we'll assume it's "Id"!
-                return new string[] { "Id" };
+                throw new ArgumentException(
+                    String.Format("The Type {0} was not found in the DbContext with Type {1}", type.Name, this.context.GetType().Name),
+                    e
+                    );
             }
+            var members = (IEnumerable<System.Data.Entity.Core.Metadata.Edm.EdmMember>)meta
+                .MetadataProperties
+                .Where(mp => mp.Name == "KeyMembers")
+                .First()
+                .Value;
+            IEnumerable<string> retval = members.Select(m => m.Name);
+            return retval;
         }
 
         /// <summary>
diff --git a/JSONAPI.EntityFramework/Properties/AssemblyInfo.cs b/JSONAPI.EntityFramework/Properties/AssemblyInfo.cs
index 1a587afe..3205b9a6 100644
--- a/JSONAPI.EntityFramework/Properties/AssemblyInfo.cs
+++ b/JSONAPI.EntityFramework/Properties/AssemblyInfo.cs
@@ -22,6 +22,8 @@
 // The following GUID is for the ID of the typelib if this project is exposed to COM
 [assembly: Guid("cdabab0c-3332-4b93-8cb6-ad521265a701")]
 
+[assembly: InternalsVisibleTo("JSONAPI.EntityFramework.Tests")]
+
 // Version information for an assembly consists of the following four values:
 //
 //      Major Version