1 files changed, 1 insertions, 1 deletions
diff --git a/compare/compare.c b/compare/compare.c
index ee1966b9..3cb3cfff 100644
--- a/compare/compare.c
+++ b/compare/compare.c
@@ -570,7 +570,7 @@ fail:
     free(pos);
     const char *fmt =
         "Usage: %s ([-i] <input-dir>)+ [-o <output-dir>] [-s <scale:1-8>] [-p <pass-level:0-3>]\n";
-    printf(fmt, argv[0]);
+    printf(fmt, argv[0] ? argv[0] : "compare");
     return NULL;
 }