diff --git a/vlib/os/os_windows.c.v b/vlib/os/os_windows.c.v
index 4804b5f055..10c6206fdb 100644
--- a/vlib/os/os_windows.c.v
+++ b/vlib/os/os_windows.c.v
@@ -383,7 +383,7 @@ pub fn is_writable_folder(folder string) ?bool {
 		return error('cannot write to folder $folder: $err')
 	}
 	f.close()
-	rm(tmp_perm_check)
+	rm(tmp_perm_check) ?
 	return true
 }