diff --git a/res/ari/ari_websockets.c b/res/ari/ari_websockets.c
index 528e7f8b2e4cdf00b5aef868feaa8b9a67f953ae..ed024377da2e5481f16b736d31e89acb8322b6f1 100644
--- a/res/ari/ari_websockets.c
+++ b/res/ari/ari_websockets.c
@@ -174,7 +174,7 @@ int ast_ari_websocket_session_write(struct ast_ari_websocket_session *session,
 		return -1;
 	}
 
-	ast_debug(3, "Examining ARI event (length %zu): \n%s\n", strlen(str), str);
+	ast_debug(3, "Examining ARI event (length %u): \n%s\n", (unsigned int) strlen(str), str);
 	if (ast_websocket_write_string(session->ws_session, str)) {
 		ast_log(LOG_NOTICE, "Problem occurred during websocket write, websocket closed\n");
 		return -1;