diff --git a/runtime/doc/diff.txt b/runtime/doc/diff.txt
index 069a853bd..81564664e 100644
--- a/runtime/doc/diff.txt
+++ b/runtime/doc/diff.txt
@@ -1,4 +1,4 @@
-*diff.txt* For Vim version 9.1. Last change: 2024 Mar 28
+*diff.txt* For Vim version 9.1. Last change: 2025 Mar 28