diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 9454bba..79d9463 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -79,3 +79,5 @@ We're much more likely to approve your changes if you:
 [open-issue]: https://github.com/uber-go/zap/issues/new
 [cla]: https://cla-assistant.io/uber-go/zap
 [commit-message]: http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html
+
+Please run gofmt before opening a pull request.
diff --git a/README.md b/README.md
index 3267cda..e28afe9 100644
--- a/README.md
+++ b/README.md
@@ -139,3 +139,5 @@ Maintained by the platform team.
 ## Run B merge check
 
 This draft is reserved for the Run B merge transition check.
+
+Please run gofmt before opening a pull request.