diff --git a/mingw-w64-headers/include/wincrypt.idl b/mingw-w64-headers/include/wincrypt.idl
index 8dcf920..5b37226 100644
--- a/mingw-w64-headers/include/wincrypt.idl
+++ b/mingw-w64-headers/include/wincrypt.idl
@@ -13,9 +13,11 @@
 
 cpp_quote("#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)")
 
+#ifndef __WIDL__
 #ifndef FARPROC
 typedef int (__stdcall FARPROC) ();
 #endif
+#endif
 
 #ifndef PBYTE
 typedef BYTE *PBYTE;