diff --git a/main/manager.c b/main/manager.c
index 5b6f821c31..39e6520544 100644
--- a/main/manager.c
+++ b/main/manager.c
@@ -1813,7 +1813,7 @@ static int action_getvar(struct mansession *s, const struct message *m)
 
 	if (varname[strlen(varname) - 1] == ')') {
 		if (!c) {
-			c = ast_channel_alloc(0, 0, "", "", "", "", "", 0, "Bogus/%p", NULL);
+			c = ast_channel_alloc(0, 0, "", "", "", "", "", 0, "Bogus/%p", SENTINEL);
 			if (c) {
 				ast_func_read(c, (char *) varname, workspace, sizeof(workspace));
 				ast_channel_free(c);