diff --git a/include/fdi.h b/include/fdi.h
index a4928b06f95..6659ce462ef 100644
--- a/include/fdi.h
+++ b/include/fdi.h
@@ -204,7 +204,7 @@ typedef struct {
 /**********************************************************************/
 
 typedef void * (__WINE_ALLOC_SIZE(1) __cdecl *PFNALLOC)(ULONG cb);
-#define FNALLOC(fn) void * __cdecl fn(ULONG cb)
+#define FNALLOC(fn) void * __WINE_ALLOC_SIZE(1) __cdecl fn(ULONG cb)
 
 typedef void (__cdecl *PFNFREE)(void *pv);
 #define FNFREE(fn) void __cdecl fn(void *pv)