diff --git a/lisp/vc/ediff.el b/lisp/vc/ediff.el
index 3a2d1e4..8723c19 100644
--- a/lisp/vc/ediff.el
+++ b/lisp/vc/ediff.el
@@ -1403,7 +1403,7 @@ ediff-patch-buffer
    patch-buf
    (read-buffer
     "Which buffer to patch? "
-    (ediff-other-buffer patch-buf))))
+    (ediff-other-buffer patch-buf) 'require-match)))
 
 
 ;;;###autoload