diff --git a/reactos/include/ddk/ddkmapi.h b/reactos/include/ddk/ddkmapi.h
index 86a13994711..4500cc6f58f 100644
--- a/reactos/include/ddk/ddkmapi.h
+++ b/reactos/include/ddk/ddkmapi.h
@@ -330,7 +330,7 @@ typedef struct _DDSETSKIPFIELD
 
 
 DXAPI
-DWORD
+DWORD PASCAL
 DxApi(IN DWORD dwFunctionNum,
       IN LPVOID lpvInBuffer,
       IN DWORD cbInBuffer,