diff --git a/reactos/include/ddk/portcls.h b/reactos/include/ddk/portcls.h
index b2ec6d7a171..0748bc5904e 100644
--- a/reactos/include/ddk/portcls.h
+++ b/reactos/include/ddk/portcls.h
@@ -1305,7 +1305,7 @@ DECLARE_INTERFACE_(IMiniportMidi, IMiniport)
     STDMETHOD_(void, Service)(THIS) PURE;
 
     STDMETHOD_(NTSTATUS, NewStream)(THIS_
-        OUT PMINIPORTMIDISTREAM Stream,
+        OUT PMINIPORTMIDISTREAM *Stream,
         IN  PUNKNOWN OuterUnknown OPTIONAL,
         IN  POOL_TYPE PoolType,
         IN  ULONG Pin,
@@ -1343,6 +1343,9 @@ DEFINE_GUIDSTRUCT("0xB4C90A30-5791-11d0-86f9-00a0c911b544", IID_IPortTopology);
 DEFINE_GUID(IID_IPortTopology, 0xb4c90a30L, 0x5791, 0x11d0, 0x86, 0xf9, 0x00, 0xa0, 0xc9, 0x11, 0xb5, 0x44);
 DEFINE_GUID(CLSID_PortTopology, 0xb4c90a32L, 0x5791, 0x11d0, 0x86, 0xf9, 0x00, 0xa0, 0xc9, 0x11, 0xb5, 0x44);
 
+#undef INTERFACE
+#define INTERFACE IPortTopology
+
 DECLARE_INTERFACE_(IPortTopology, IPort)
 {
     DEFINE_ABSTRACT_UNKNOWN()
@@ -1363,6 +1366,9 @@ typedef IPortTopology *PPORTTOPOLOGY;
 
 DEFINE_GUID(IID_IMiniportTopology, 0xb4c90a31L, 0x5791, 0x11d0, 0x86, 0xf9, 0x00, 0xa0, 0xc9, 0x11, 0xb5, 0x44);
 
+#undef INTERFACE
+#define INTERFACE IMiniportTopology
+
 DECLARE_INTERFACE_(IMiniportTopology,IMiniport)
 {
     DEFINE_ABSTRACT_UNKNOWN()