diff --git a/res/res_calendar.c b/res/res_calendar.c
index b775537817..604d0b5c49 100644
--- a/res/res_calendar.c
+++ b/res/res_calendar.c
@@ -694,7 +694,7 @@ static void *do_notify(void *data)
 {
 	struct ast_calendar_event *event = data;
 	struct ast_dial *dial = NULL;
-	struct ast_str *apptext = NULL, *tmpstr;
+	struct ast_str *apptext = NULL, *tmpstr = NULL;
 	struct ast_datastore *datastore;
 	enum ast_dial_result res;
 	struct ast_channel *chan = NULL;