diff --git a/lisp/vc/diff-mode.el b/lisp/vc/diff-mode.el
index 0f393ba86a2..66043059d14 100644
--- a/lisp/vc/diff-mode.el
+++ b/lisp/vc/diff-mode.el
@@ -1619,7 +1619,7 @@ modified lines of the diff."
                   nil)))
   (when (eq diff-buffer-type 'git)
     (setq diff-outline-regexp
-          (concat "\\(^diff --git.*\n\\|" diff-hunk-header-re "\\)")))
+          (concat "\\(^diff --git.*\\|" diff-hunk-header-re "\\)")))
   (setq-local outline-level #'diff--outline-level)
   (setq-local outline-regexp diff-outline-regexp))