Index: apps/app_queue.c
===================================================================
--- apps/app_queue.c	(revision 90148)
+++ apps/app_queue.c	(working copy)
@@ -4999,7 +4999,7 @@
 
 	if (ast_strlen_zero(penalty_s))
 		penalty = 0;
-	else if (sscanf(penalty_s, "%d", &penalty) != 1)
+	else if ((sscanf(penalty_s, "%d", &penalty) != 1) || penalty < 0)
 		penalty = 0;
 
 	if (ast_strlen_zero(paused_s))