diff --git a/dlls/amstream/amstream.c b/dlls/amstream/amstream.c
index c74846c319b..9b2d41d97fb 100644
--- a/dlls/amstream/amstream.c
+++ b/dlls/amstream/amstream.c
@@ -46,6 +46,9 @@ HRESULT AM_create(IUnknown *pUnkOuter, LPVOID *ppObj)
     IAMMultiMediaStreamImpl* object; 
 
     FIXME("(%p,%p)\n", pUnkOuter, ppObj);
+
+    if( pUnkOuter )
+      return CLASS_E_NOAGGREGATION;
       
     object = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(IAMMultiMediaStreamImpl));
     
diff --git a/dlls/itss/itss.c b/dlls/itss/itss.c
index e7c415795fb..083539b3554 100644
--- a/dlls/itss/itss.c
+++ b/dlls/itss/itss.c
@@ -384,6 +384,9 @@ static HRESULT ITSS_create(IUnknown *pUnkOuter, LPVOID *ppObj)
 {
     ITStorageImpl *its;
 
+    if( pUnkOuter )
+        return CLASS_E_NOAGGREGATION;
+
     its = HeapAlloc( GetProcessHeap(), 0, sizeof(ITStorageImpl) );
     its->vtbl_IITStorage = &ITStorageImpl_Vtbl;
     its->ref = 1;
diff --git a/dlls/quartz/filesource.c b/dlls/quartz/filesource.c
index 037cc2c4d43..90ef4c91637 100644
--- a/dlls/quartz/filesource.c
+++ b/dlls/quartz/filesource.c
@@ -293,7 +293,12 @@ static HRESULT GetClassMediaFile(IAsyncReader * pReader, LPCOLESTR pszFileName,
 
 HRESULT AsyncReader_create(IUnknown * pUnkOuter, LPVOID * ppv)
 {
-    AsyncReader * pAsyncRead = CoTaskMemAlloc(sizeof(AsyncReader));
+    AsyncReader *pAsyncRead;
+    
+    if( pUnkOuter )
+        return CLASS_E_NOAGGREGATION;
+    
+    pAsyncRead = CoTaskMemAlloc(sizeof(AsyncReader));
 
     if (!pAsyncRead)
         return E_OUTOFMEMORY;
diff --git a/dlls/quartz/filtergraph.c b/dlls/quartz/filtergraph.c
index 8fc417b0b79..b56e8d98e3e 100644
--- a/dlls/quartz/filtergraph.c
+++ b/dlls/quartz/filtergraph.c
@@ -2416,6 +2416,9 @@ HRESULT FILTERGRAPH_create(IUnknown *pUnkOuter, LPVOID *ppObj) {
 
     TRACE("(%p,%p)\n", pUnkOuter, ppObj);
 
+    if( pUnkOuter )
+        return CLASS_E_NOAGGREGATION;
+
     fimpl = (IFilterGraphImpl *) HeapAlloc(GetProcessHeap(), 0, sizeof(*fimpl));
     fimpl->IGraphBuilder_vtbl = &IGraphBuilder_VTable;
     fimpl->IMediaControl_vtbl = &IMediaControl_VTable;