diff --git a/dlls/msident/msident.c b/dlls/msident/msident.c
index c12c19b5102..3efb190a39c 100644
--- a/dlls/msident/msident.c
+++ b/dlls/msident/msident.c
@@ -27,9 +27,9 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(msident);
 
-static inline void *heap_alloc(size_t len)
+static inline void* __WINE_ALLOC_SIZE(1) heap_alloc(size_t size)
 {
-    return HeapAlloc(GetProcessHeap(), 0, len);
+    return HeapAlloc(GetProcessHeap(), 0, size);
 }
 
 static inline BOOL heap_free(void *mem)