diff --git a/usr.sbin/syslogd/syslogd.c b/usr.sbin/syslogd/syslogd.c
index 2b9b4c92d11b..2405748a5ace 100644
--- a/usr.sbin/syslogd/syslogd.c
+++ b/usr.sbin/syslogd/syslogd.c
@@ -804,7 +804,7 @@ logmsg(int pri, const char *msg, const char *from, int flags)
 
 	/* extract program name */
 	for (i = 0; i < NAME_MAX; i++) {
-		if (!isalnum(msg[i]))
+		if (!isprint(msg[i]) || msg[i] == ':' || msg[i] == '[')
 			break;
 		prog[i] = msg[i];
 	}