diff --git a/main/pbx.c b/main/pbx.c
index e0fc3cbeed7b2df38bfc8ded1a0bf486eee1d953..19b284c83f3e83ddf0a69cad00a2bc5d07bbd358 100644
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -7891,17 +7891,17 @@ static int manager_show_dialplan(struct mansession *s, const struct message *m)
 
 	manager_show_dialplan_helper(s, m, idtext, context, exten, &counters, NULL);
 
-	if (context && !counters.context_existence) {
+	if (!ast_strlen_zero(context) && !counters.context_existence) {
 		char errorbuf[BUFSIZ];
 
 		snprintf(errorbuf, sizeof(errorbuf), "Did not find context %s", context);
 		astman_send_error(s, m, errorbuf);
 		return 0;
 	}
-	if (exten && !counters.extension_existence) {
+	if (!ast_strlen_zero(exten) && !counters.extension_existence) {
 		char errorbuf[BUFSIZ];
 
-		if (context)
+		if (!ast_strlen_zero(context))
 			snprintf(errorbuf, sizeof(errorbuf), "Did not find extension %s@%s", exten, context);
 		else
 			snprintf(errorbuf, sizeof(errorbuf), "Did not find extension %s in any context", exten);
@@ -7909,6 +7909,10 @@ static int manager_show_dialplan(struct mansession *s, const struct message *m)
 		return 0;
 	}
 
+	if (!counters.total_items) {
+		manager_dpsendack(s, m);
+	}
+
 	astman_append(s, "Event: ShowDialPlanComplete\r\n"
 		"EventList: Complete\r\n"
 		"ListItems: %d\r\n"