diff -r -U4 vixie-cron-4.1/do_command.c vixie-cron-4.1+safe/do_command.c
--- vixie-cron-4.1/do_command.c	2004-08-27 19:09:34.000000000 +0100
+++ vixie-cron-4.1+safe/do_command.c	2010-05-13 23:00:43.000000000 +0100
@@ -510,9 +510,9 @@
 }
 
 static int
 safe_p(const char *usernm, const char *s) {
-	static const char safe_delim[] = "@!:%-.,";     /* conservative! */
+	static const char safe_delim[] = "_@!:%-.,";     /* conservative! */
 	const char *t;
 	int ch, first;
 
 	for (t = s, first = 1; (ch = *t++) != '\0'; first = 0) {