diff --git a/src/os_w32exe.c b/src/os_w32exe.c
index 76f9332..93a1389 100644
--- a/src/os_w32exe.c
+++ b/src/os_w32exe.c
@@ -129,7 +129,8 @@
 errout:
 #endif
     free(argv);
-    free(tofree);
+    if (tofree != NULL)
+	free(tofree);
 #ifdef FEAT_MBYTE
     free_cmd_argsW();
 #endif