diff --git a/reactos/include/ddk/portcls.h b/reactos/include/ddk/portcls.h
index 5c787181714..69451f2ccc1 100644
--- a/reactos/include/ddk/portcls.h
+++ b/reactos/include/ddk/portcls.h
@@ -1080,6 +1080,9 @@ DEFINE_GUID(IID_IPort,
         IN  ULONG CreateOptiona OPTIONAL, \
         OUT PULONG Disposition OPTIONAL);
 
+#undef INTERFACE
+#define INTERFACE IPort
+
 DECLARE_INTERFACE_(IPort, IUnknown)
 {
     DEFINE_ABSTRACT_UNKNOWN()