diff --git a/ChangeLog b/ChangeLog
index 21417e6be..c5398522b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+20100304
+ - (djm) [ssh-keygen.c] Use correct local variable, instead of
+   maybe-undefined global "optarg"
+
 20100303
  - (djm) [PROTOCOL.certkeys] Add RCS Ident
  - OpenBSD CVS Sync
diff --git a/ssh-keygen.c b/ssh-keygen.c
index 7dc10808c..f910dce38 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1300,7 +1300,7 @@ parse_cert_times(char *timespec)
 	from = xstrdup(timespec);
 	to = strchr(from, ':');
 	if (to == NULL || from == to || *(to + 1) == '\0')
-		fatal("Invalid certificate life specification %s", optarg);
+		fatal("Invalid certificate life specification %s", timespec);
 	*to++ = '\0';
 
 	if (*from == '-' || *from == '+')