diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 9790620ea9..a540fe8604 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -116,6 +116,7 @@ To create a new PR, fork the project in GitHub and clone the upstream repo:
 > **Note**
 > Please fork to a personal GitHub account rather than a corporate/enterprise
 > one so maintainers can push commits to your branch.
+> **Pull requests from protected forks will not be accepted.**
 
 ```sh
 git clone https://github.com/open-telemetry/opentelemetry-demo.git