diff --git a/.gitignore b/.gitignore
index 72ab9c5..e327939 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,9 @@
 /Win32
 /Win64
 
+Build/TestAndBuild.fb7lck
+*.fbl7
+*.fbpInf
+*.rc
+*.drc
+*.map
diff --git a/Build/TestAndBuild.fbp7 b/Build/TestAndBuild.fbp7
new file mode 100644
index 0000000..f8345fa
Binary files /dev/null and b/Build/TestAndBuild.fbp7 differ
diff --git a/Delphi.Mocks.InterfaceProxy.pas b/Delphi.Mocks.InterfaceProxy.pas
index bbd2284..2972aac 100644
--- a/Delphi.Mocks.InterfaceProxy.pas
+++ b/Delphi.Mocks.InterfaceProxy.pas
@@ -30,15 +30,15 @@ interface
 uses
   Rtti,
   SysUtils,
+  Generics.Collections,
   Delphi.Mocks,
   Delphi.Mocks.Interfaces,
-  //  Delphi.Mocks.VirtualInterface,
   Delphi.Mocks.ProxyBase;
 
 type
   TProxyBaseInvokeEvent = procedure (Method: TRttiMethod; const Args: TArray<TValue>; out Result: TValue) of object;
 
-  TSetupMode = (None,Behavior,Expectation);
+  TSetupMode = (None, Behavior, Expectation);
 
   TInterfaceProxy<T> = class(TBaseProxy<T>)
   private type
@@ -51,11 +51,12 @@     TProxyVirtualInterface = class(TVirtualInterface)
       constructor Create(AProxy : TInterfaceProxy<T>; AInterface: Pointer; InvokeEvent: TVirtualInterfaceInvokeEvent);
     end;
   private
-    FVirtualInterface : IInterface;
+    FVirtualInterfaces : TDictionary<TGUID, TProxyVirtualInterface>;
   protected
     function InternalQueryInterface(const IID: TGUID; out Obj): HRESULT; stdcall;
     function QueryInterface(const IID: TGUID; out Obj): HRESULT; override;
     function Proxy : T;override;
+    function CastAs<I: IInterface> : I;
   public
     constructor Create;override;
     destructor Destroy;override;
@@ -69,22 +70,40 @@ implementation
 
 { TInterfaceProxy<T> }
 
+function TInterfaceProxy<T>.CastAs<I>: I;
+var
+  virtualProxy : TProxyVirtualInterface;
+begin
+  virtualProxy := TProxyVirtualInterface.Create(Self, TypeInfo(I), Self.DoInvoke);
+
+  FVirtualInterfaces.Add(GetTypeData(TypeInfo(I)).Guid, virtualProxy);
+end;
+
 constructor TInterfaceProxy<T>.Create;
+var
+  virtualProxy : TProxyVirtualInterface;
 begin
   inherited;
-  FVirtualInterface := TProxyVirtualInterface.Create(Self,TypeInfo(T),Self.DoInvoke);
+
+  FVirtualInterfaces := TDictionary<TGUID, TProxyVirtualInterface>.Create;
+
+  virtualProxy := TProxyVirtualInterface.Create(Self, TypeInfo(T), Self.DoInvoke);
+
+  FVirtualInterfaces.Add(GetTypeData(TypeInfo(T)).Guid, virtualProxy);
 end;
 
 destructor TInterfaceProxy<T>.Destroy;
 begin
-  FVirtualInterface := nil;
+  FVirtualInterfaces.Clear;
+  FreeAndNil(FVirtualInterfaces);
+
   inherited;
 end;
 
 function TInterfaceProxy<T>.InternalQueryInterface(const IID: TGUID; out Obj): HRESULT;
 begin
   Result := E_NOINTERFACE;
-  if (IsEqualGUID(IID,IInterface)) then
+  if (IsEqualGUID(IID, IInterface)) then
     if GetInterface(IID, Obj) then
       Result := 0;
 end;
@@ -92,30 +111,44 @@ function TInterfaceProxy<T>.InternalQueryInterface(const IID: TGUID; out Obj): H
 function TInterfaceProxy<T>.Proxy: T;
 var
   pInfo : PTypeInfo;
+  virtualProxy : IInterface;
 begin
   pInfo := TypeInfo(T);
-  if FVirtualInterface.QueryInterface(GetTypeData(pInfo).Guid,result) <> 0 then
+
+  if FVirtualInterfaces.ContainsKey(GetTypeData(pInfo).Guid) then
+    virtualProxy := FVirtualInterfaces.Items[GetTypeData(pInfo).Guid]
+  else
+    raise EMockNoProxyException.Create('Error proxy casting to interface');
+
+  if virtualProxy.QueryInterface(GetTypeData(pInfo).Guid,result) <> 0 then
     raise EMockNoProxyException.Create('Error casting to interface ' + string(pInfo.Name) + ' , proxy does not appear to implememnt T');
 end;
 
 function TInterfaceProxy<T>.QueryInterface(const IID: TGUID; out Obj): HRESULT;
+var
+  virtualProxy : IInterface;
 begin
   Result := E_NOINTERFACE;
-  if (FVirtualInterface <> nil) then
-    Result := FVirtualInterface.QueryInterface(IID, Obj);
+
+  if (FVirtualInterfaces <> nil) then
+    if (FVirtualInterfaces.Count <> 0) then
+      if (FVirtualInterfaces.ContainsKey(IID)) then
+      begin
+        virtualProxy := FVirtualInterfaces.Items[IID];
+        Result := virtualProxy.QueryInterface(IID, Obj);
+      end;
+
   if result <> 0 then
     Result := inherited;
-
 end;
 
 { TInterfaceProxy<T>.TProxyVirtualInterface }
 
-constructor TInterfaceProxy<T>.TProxyVirtualInterface.Create(
-  AProxy: TInterfaceProxy<T>; AInterface: Pointer;
-  InvokeEvent: TVirtualInterfaceInvokeEvent);
+constructor TInterfaceProxy<T>.TProxyVirtualInterface.Create(AProxy: TInterfaceProxy<T>;
+  AInterface: Pointer; InvokeEvent: TVirtualInterfaceInvokeEvent);
 begin
   FProxy := AProxy;
-  inherited Create(Ainterface,InvokeEvent);
+  inherited Create(Ainterface, InvokeEvent);
 end;
 
 
diff --git a/Sample1.RES b/Sample1.RES
index adc2449..c0e155d 100644
Binary files a/Sample1.RES and b/Sample1.RES differ
diff --git a/Tests/Delphi.Mocks.Tests.InterfaceProxy.pas b/Tests/Delphi.Mocks.Tests.InterfaceProxy.pas
new file mode 100644
index 0000000..c532ed7
--- /dev/null
+++ b/Tests/Delphi.Mocks.Tests.InterfaceProxy.pas
@@ -0,0 +1,91 @@
+{***************************************************************************}
+{                                                                           }
+{           Delphi.Mocks                                                    }
+{                                                                           }
+{           Copyright (C) 2011 Vincent Parrett                              }
+{                                                                           }
+{           http://www.finalbuilder.com                                     }
+{                                                                           }
+{                                                                           }
+{***************************************************************************}
+{                                                                           }
+{  Licensed under the Apache License, Version 2.0 (the "License");          }
+{  you may not use this file except in compliance with the License.         }
+{  You may obtain a copy of the License at                                  }
+{                                                                           }
+{      http://www.apache.org/licenses/LICENSE-2.0                           }
+{                                                                           }
+{  Unless required by applicable law or agreed to in writing, software      }
+{  distributed under the License is distributed on an "AS IS" BASIS,        }
+{  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. }
+{  See the License for the specific language governing permissions and      }
+{  limitations under the License.                                           }
+{                                                                           }
+{***************************************************************************}
+
+unit Delphi.Mocks.Tests.InterfaceProxy;
+
+interface
+
+uses
+  TestFramework;
+
+type
+  {$M+}
+  ISimpleInterface = Interface
+  ['{F1731F12-2453-4818-A785-997AF7A3D51F}']
+  End;
+
+  ISecondSimpleInterface = Interface
+  ['{C7191239-2E89-4D3A-9D1B-F894BACBBB39}']
+  End;
+  {$M-}
+
+  TTestInterfaceProxy = class(TTestCase)
+  published
+    procedure Does_A_Proxy_Implement_Two_Interfaces_After_A_Cast;
+    procedure After_Destruction_Are_All_The_Interfaces_Cleaned_Up;
+  end;
+
+//TODO: IProxy<T> will not allow a function of CastAs<I> on it, class does however.
+
+implementation
+
+uses
+  SysUtils,
+  Delphi.Mocks,
+  Delphi.Mocks.InterfaceProxy;
+
+{ TTestInterfaceProxy }
+
+procedure TTestInterfaceProxy.After_Destruction_Are_All_The_Interfaces_Cleaned_Up;
+var
+  simpleInterface: TInterfaceProxy<ISimpleInterface>;
+  secondInterface: ISecondSimpleInterface;
+begin
+  simpleInterface := TInterfaceProxy<ISimpleInterface>.Create;
+  secondInterface := simpleInterface.CastAs<ISecondSimpleInterface>;
+
+  CheckNotNull(secondInterface, 'The second interface is not implemented!');
+end;
+
+procedure TTestInterfaceProxy.Does_A_Proxy_Implement_Two_Interfaces_After_A_Cast;
+var
+  simpleInterface: TInterfaceProxy<ISimpleInterface>;
+  secondInterface : ISecondSimpleInterface;
+begin
+  simpleInterface := TInterfaceProxy<ISimpleInterface>.Create;
+  try
+    simpleInterface.CastAs<ISecondSimpleInterface>;
+
+    simpleInterface.QueryInterface(ISecondSimpleInterface, secondInterface);
+
+    CheckNotNull(secondInterface, 'The second interface is not implemented!');
+  finally
+    FreeAndNil(simpleInterface);
+  end;
+end;
+
+initialization
+  TestFramework.RegisterTest(TTestInterfaceProxy.Suite);
+end.
diff --git a/Tests/Delphi.Mocks.Tests.OpenArrayIntf.pas b/Tests/Delphi.Mocks.Tests.OpenArrayIntf.pas
index 2c4cc7b..69a20e9 100644
--- a/Tests/Delphi.Mocks.Tests.OpenArrayIntf.pas
+++ b/Tests/Delphi.Mocks.Tests.OpenArrayIntf.pas
@@ -44,7 +44,7 @@ procedure TestIOpenArray.TestMyMethodDynamicArray;
 
   Intf := Mock;
 
-  // privileged instruction :-(
+  //TODO: Fix the privileged instruction. Something to do with TValue not liking Dynamic Arrays
   CheckEquals(3, Intf.MyMethod([Obj], 1));
 end;
 
diff --git a/Tests/Delphi.Mocks.Tests.dpr b/Tests/Delphi.Mocks.Tests.dpr
index db01c5b..aaedf36 100644
--- a/Tests/Delphi.Mocks.Tests.dpr
+++ b/Tests/Delphi.Mocks.Tests.dpr
@@ -46,7 +46,8 @@ uses
   Delphi.Mocks.Tests.Base in 'Delphi.Mocks.Tests.Base.pas',
   Delphi.Mocks.Tests.ObjectProxy in 'Delphi.Mocks.Tests.ObjectProxy.pas',
   Delphi.Mocks.Examples.Objects in 'Delphi.Mocks.Examples.Objects.pas',
-  Delphi.Mocks.ReturnTypePatch in '..\Delphi.Mocks.ReturnTypePatch.pas';
+  Delphi.Mocks.ReturnTypePatch in '..\Delphi.Mocks.ReturnTypePatch.pas',
+  Delphi.Mocks.Tests.InterfaceProxy in 'Delphi.Mocks.Tests.InterfaceProxy.pas';
 
 {$R *.RES}
 
diff --git a/Tests/Delphi.Mocks.Tests.dproj b/Tests/Delphi.Mocks.Tests.dproj
index 1cc9354..c436221 100644
--- a/Tests/Delphi.Mocks.Tests.dproj
+++ b/Tests/Delphi.Mocks.Tests.dproj
@@ -112,6 +112,13 @@
 			<DCCReference Include="Delphi.Mocks.Tests.TValue.pas"/>
 			<DCCReference Include="Delphi.Mocks.Tests.Interfaces.pas"/>
 			<DCCReference Include="Delphi.Mocks.Tests.OpenArrayIntf.pas"/>
+			<DCCReference Include="Delphi.Mocks.Tests.MethodData.pas"/>
+			<DCCReference Include="Delphi.Mocks.Tests.ProxyBase.pas"/>
+			<DCCReference Include="Delphi.Mocks.Tests.Base.pas"/>
+			<DCCReference Include="Delphi.Mocks.Tests.ObjectProxy.pas"/>
+			<DCCReference Include="Delphi.Mocks.Examples.Objects.pas"/>
+			<DCCReference Include="..\Delphi.Mocks.ReturnTypePatch.pas"/>
+			<DCCReference Include="Delphi.Mocks.Tests.InterfaceProxy.pas"/>
 			<BuildConfiguration Include="Release">
 				<Key>Cfg_2</Key>
 				<CfgParent>Base</CfgParent>
@@ -178,19 +185,3 @@
 		<Import Condition="Exists('$(BDS)\Bin\CodeGear.Delphi.Targets')" Project="$(BDS)\Bin\CodeGear.Delphi.Targets"/>
 		<Import Condition="Exists('$(APPDATA)\Embarcadero\$(BDSAPPDATABASEDIR)\$(PRODUCTVERSION)\UserTools.proj')" Project="$(APPDATA)\Embarcadero\$(BDSAPPDATABASEDIR)\$(PRODUCTVERSION)\UserTools.proj"/>
 	</Project>
-
-<!-- EurekaLog First Line
-[Exception Log]
-EurekaLog Version=7001
-Activate=0
-atVCL=1
-DeleteMapAfterCompile=0
-dpJCL=1
-Encrypt Password=""
-idEurekaLog=1
-idEurekaLogDetailed=1
-idMSClassic=1
-idStepsToReproduce=1
-ProjectID="{CC1138A4-84AF-46ED-8D02-81B0C9B1C1C5}"
-sndShowFailureMsg=1
-EurekaLog Last Line -->
diff --git a/Tests/Delphi.Mocks.Tests.res b/Tests/Delphi.Mocks.Tests.res
index 15f1ffe..5dd56e5 100644
Binary files a/Tests/Delphi.Mocks.Tests.res and b/Tests/Delphi.Mocks.Tests.res differ