diff --git a/lisp/emacs-lisp/lisp.el b/lisp/emacs-lisp/lisp.el
index a4aa79c171e..ee481dc4ed3 100644
--- a/lisp/emacs-lisp/lisp.el
+++ b/lisp/emacs-lisp/lisp.el
@@ -422,7 +422,8 @@ of a defun, nil if it failed to find one."
 				       "\\(?:" defun-prompt-regexp "\\)\\s(")
 			     "^\\s(")
 			                      nil 'move arg))
-                    (nth 8 (syntax-ppss))))
+                    (save-match-data
+                      (nth 8 (syntax-ppss)))))
            found)
 	 (progn (goto-char (1- (match-end 0)))
                 t)))