diff -r cfe13185fd02 -r 6d97eb820cc1 thermferm/websocket.c
--- a/thermferm/websocket.c	Sat Apr 20 11:34:00 2024 +0200
+++ b/thermferm/websocket.c	Sat Apr 20 11:48:20 2024 +0200
@@ -347,7 +347,7 @@
 
 		memcpy(buf, in, len);
 		buf[len] = '\0';
-		syslog(LOG_NOTICE, "ws: received %ld bytes %s", len, buf);
+		syslog(LOG_NOTICE, "ws: received %ld bytes %s", (long)len, buf);
 		/*
 		 * These are send by bmsapp to bmsd. Then bmsd resends these via MQTT.
 		 * Do we want to change that? Or use it for the new web pages.