diff --git a/src/os_win16.c b/src/os_win16.c
index 2afaddc..1cf3ff8 100644
--- a/src/os_win16.c
+++ b/src/os_win16.c
@@ -121,7 +121,8 @@
     pmain(argc, argv);
 
     free(argv);
-    free(tofree);
+    if (tofree != NULL)
+	free(tofree);
 
     return 0;
 }