diff --git a/src/urclock.c b/src/urclock.c
index 4abfd572..c29a2090 100644
--- a/src/urclock.c
+++ b/src/urclock.c
@@ -2208,6 +2208,9 @@ static int urclock_initialize(const PROGRAMMER *pgm, const AVRPART *p) {
 static void urclock_disable(const PROGRAMMER *pgm) {
   unsigned char buf[16];
 
+  if(ur.urprotocol)
+    return;
+
   buf[0] = Cmnd_STK_LEAVE_PROGMODE;
   buf[1] = Sync_CRC_EOP;