diff --git a/src/diff.c b/src/diff.c
index cc9e6de..c67654f 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -2141,6 +2141,13 @@
     exarg_T	ea;
     char_u	buf[30];
 
+#ifdef FEAT_JOB_CHANNEL
+    if (bt_prompt(curbuf))
+    {
+	vim_beep(BO_OPER);
+	return;
+    }
+#endif
     if (count == 0)
 	ea.arg = (char_u *)"";
     else