diff --git a/lisp/vc/diff-mode.el b/lisp/vc/diff-mode.el
index 99ac50c155a..ac7d55c8a46 100644
--- a/lisp/vc/diff-mode.el
+++ b/lisp/vc/diff-mode.el
@@ -2353,7 +2353,7 @@ by `diff-refine-hunk'."
                                         (match-end 0)
                                         'diff-refine-removed))
              (goto-char middle)
-             (while (re-search-forward "^\\(?:+.*\n\\)+" end t)
+             (while (re-search-forward "^\\(?:\\+.*\n\\)+" end t)
                (diff--refine-propertize (match-beginning 0)
                                         (match-end 0)
                                         'diff-refine-added))))))