diff --git a/rostests/winetests/advapi32/registry.c b/rostests/winetests/advapi32/registry.c
index a3d9f300672..47e76b28634 100644
--- a/rostests/winetests/advapi32/registry.c
+++ b/rostests/winetests/advapi32/registry.c
@@ -52,7 +52,11 @@ static char *get_temp_buffer( int size )
     UINT idx;
 
     idx = ++pos % (sizeof(list)/sizeof(list[0]));
-    if ((ret = realloc( list[idx], size ))) list[idx] = ret;
+    if (list[idx])
+        ret = HeapReAlloc( GetProcessHeap(), 0, list[idx], size );
+    else
+        ret = HeapAlloc( GetProcessHeap(), 0, size );
+    if (ret) list[idx] = ret;
     return ret;
 }