diff --git a/README.md b/README.md
index 5519e9aa5..3ff899116 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 # repo
 
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/README.md
+
 Repo is a tool built on top of Git.  Repo helps manage many Git repositories,
 does the uploads to revision control systems, and automates parts of the
 development workflow.  Repo is not meant to replace Git, only to make it
diff --git a/SUBMITTING_PATCHES.md b/SUBMITTING_PATCHES.md
index c51fac0b3..e02a753da 100644
--- a/SUBMITTING_PATCHES.md
+++ b/SUBMITTING_PATCHES.md
@@ -1,3 +1,6 @@
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/SUBMITTING_PATCHES.md
+
 [TOC]
 
 # Short Version
diff --git a/docs/internal-fs-layout.md b/docs/internal-fs-layout.md
index 3537dfda1..e9446ef46 100644
--- a/docs/internal-fs-layout.md
+++ b/docs/internal-fs-layout.md
@@ -1,5 +1,8 @@
 # Repo internal filesystem layout
 
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/docs/internal-fs-layout.md
+
 A reference to the `.repo/` tree in repo client checkouts.
 Hopefully it's complete & up-to-date, but who knows!
 
diff --git a/docs/manifest-format.md b/docs/manifest-format.md
index 676e031d8..bdb0ee87e 100644
--- a/docs/manifest-format.md
+++ b/docs/manifest-format.md
@@ -1,5 +1,8 @@
 # repo Manifest Format
 
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
+
 A repo manifest describes the structure of a repo client; that is
 the directories that are visible and where they should be obtained
 from with git.
diff --git a/docs/python-support.md b/docs/python-support.md
index a5c490a89..f2062b462 100644
--- a/docs/python-support.md
+++ b/docs/python-support.md
@@ -1,5 +1,8 @@
 # Supported Python Versions
 
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/docs/python-support.md
+
 With Python 2.7 officially going EOL on [01 Jan 2020](https://pythonclock.org/),
 we need a support plan for the repo project itself.
 Inevitably, there will be a long tail of users who still want to use Python 2 on
diff --git a/docs/release-process.md b/docs/release-process.md
index 0df590ac5..170dbc253 100644
--- a/docs/release-process.md
+++ b/docs/release-process.md
@@ -1,5 +1,8 @@
 # repo release process
 
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/docs/release-process.md
+
 This is the process for creating a new release of repo, as well as all the
 related topics and flows.
 
diff --git a/docs/repo-hooks.md b/docs/repo-hooks.md
index 7c37c30e7..6c5eac3cc 100644
--- a/docs/repo-hooks.md
+++ b/docs/repo-hooks.md
@@ -1,5 +1,8 @@
 # repo hooks
 
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/docs/repo-hooks.md
+
 [TOC]
 
 Repo provides a mechanism to hook specific stages of the runtime with custom
diff --git a/docs/windows.md b/docs/windows.md
index 4282bebfd..7453188a3 100644
--- a/docs/windows.md
+++ b/docs/windows.md
@@ -1,5 +1,8 @@
 # Microsoft Windows Details
 
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/docs/windows.md
+
 Repo is primarily developed on Linux with a lot of users on macOS.
 Windows is, unfortunately, not a common platform.
 There is support in repo for Windows, but there might be some rough edges.
diff --git a/release/README.md b/release/README.md
index 3b81d5324..7f3a5e9d3 100644
--- a/release/README.md
+++ b/release/README.md
@@ -1,2 +1,5 @@
+> **Warning: The "master" branch is no longer used.  Use "main" instead.**<br>
+> https://gerrit.googlesource.com/git-repo/+/HEAD/release/README.md
+
 These are helper tools for managing official releases.
 See the [release process](../docs/release-process.md) document for more details.