diff --git a/clang/tools/clang-format/clang-format.el b/clang/tools/clang-format/clang-format.el
index 48fe36f2e5635a7c758b682e8d18502c8f54656c..b0131ed31949915d2492b8e104b3401c755ec098 100644
--- a/clang/tools/clang-format/clang-format.el
+++ b/clang/tools/clang-format/clang-format.el
@@ -28,6 +28,7 @@
 
 (defun clang-format-buffer ()
   "Use clang-format to format the current buffer."
+  (interactive)
   (clang-format (point-min) (point-max)))
 
 (defun clang-format (begin end)