diff --git a/apps/app_zapateller.c b/apps/app_zapateller.c
index 06941b16a5..5a209e3152 100644
--- a/apps/app_zapateller.c
+++ b/apps/app_zapateller.c
@@ -85,7 +85,7 @@ static int zapateller_exec(struct ast_channel *chan, void *data)
 			res = ast_safe_sleep(chan, 500);
 		}
 	}
-	if (chan->cid.cid_num && nocallerid) {
+	if (!ast_strlen_zero(chan->cid.cid_num) && nocallerid) {
 		ast_module_user_remove(u);
 		return res;
 	}