diff --git a/config/feature_flags/development/merge_commit_diff_modes.yml b/config/feature_flags/development/merge_commit_diff_modes.yml
index 2da966e1cbbaf634cc63abce2cf67b8857d91e02..d550ae9aba0d4866df69010aece83185a1261109 100644
--- a/config/feature_flags/development/merge_commit_diff_modes.yml
+++ b/config/feature_flags/development/merge_commit_diff_modes.yml
@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/415579
 milestone: '16.1'
 type: development
 group: group::source code
-default_enabled: false
+default_enabled: true
diff --git a/doc/user/project/file_lock.md b/doc/user/project/file_lock.md
index 2a23bf57786517a4ff93b3aa8803ef6d695851de..a0058c8b8b0081274b7f79ccdce7eecdaf2c0964 100644
--- a/doc/user/project/file_lock.md
+++ b/doc/user/project/file_lock.md
@@ -40,6 +40,16 @@ users are prevented from modifying locked files by pushing, merging,
 or any other means, and are shown an error like: `The path '.gitignore' is
 locked by Administrator`.
 
+NOTE:
+There is a bug which blocks changes which include a merged file locked by
+another user. In 16.1 we introduced `merge_commit_diff_modes` feature flag,
+disabled by default. When `merge_commit_diff_modes` is enabled merge commits
+with no additional changes are not evaluated. Merge commits with additional
+changes only evaluate the changes that were added by the committer.
+In 16.3 `merge_commit_diff_modes` is enabled by default for self-managed
+instances.
+For more information see [Issue 23625](https://gitlab.com/gitlab-org/gitlab/-/issues/23625).
+
 ## Exclusive file locks
 
 This process allows you to lock single files or file extensions and it is