diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 4180d06f7..4eceade1a 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -19,6 +19,8 @@ Prometheus uses GitHub to manage reviews of pull requests.
   Practices for Production
   Environments](http://peter.bourgon.org/go-in-production/#formatting-and-style).
 
+* Be sure to sign off on the [DCO](https://github.com/probot/dco#how-it-works)
+
 
 ## Steps to Contribute