diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d2a93b676..b1fd9e0ef 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -124,3 +124,16 @@ The script will:
    (including the stable `Metrics.java` extends clause).
 
 Add the updated files to Git and commit them.
+
+## Submit a pull request
+
+Effective 2026-06-22, all Grafana Labs repositories [require signed commits][signed-commits].
+To learn more about Git commit verification, refer to [About commit signature verification][signing-commits]
+and [Checking your commit signature verification status][verifying-commits].
+
+> [!NOTE]
+> Pull requests containing any unsigned commits cannot be merged until all commits are signed.
+
+[signed-commits]: https://docs.github.com/repositories/configuring-branches-and-merges-in-your-repository/managing-protected-branches/about-protected-branches#require-signed-commits
+[signing-commits]: https://docs.github.com/authentication/managing-commit-signature-verification/about-commit-signature-verification
+[verifying-commits]: https://docs.github.com/authentication/troubleshooting-commit-signature-verification/checking-your-commit-and-tag-signature-verification-status