diff --git a/res/res_calendar_ews.c b/res/res_calendar_ews.c
index f55a73df4e..840ca104e3 100644
--- a/res/res_calendar_ews.c
+++ b/res/res_calendar_ews.c
@@ -604,7 +604,7 @@ static int ewscal_write_event(struct ast_calendar_event *event)
 	/* Event categories*/
 	if (strlen(event->categories) > 0) {
 		ast_str_append(&request, 0, "<Categories>");
-		categories = strdupa(event->categories);	/* Duplicate string, since strsep() is destructive */
+		categories = ast_strdupa(event->categories);	/* Duplicate string, since strsep() is destructive */
 		category = strsep(&categories, ",");
 		while (category != NULL) {
 			ast_str_append(&request, 0, "<String>%s</String>", category);