diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a33becfbb1..6bb9e5df41 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -8,3 +8,7 @@ Docker does things, you'll feel right at home.
 Please [sign your work](https://github.com/docker/docker/blob/master/CONTRIBUTING.md#sign-your-work) before creating a pull request.
 
 Thanks for taking the time to improve the Docker Toolbox!
+
+## License
+
+By contributing your code, you agree to license your contribution under the [Apache license](https://github.com/docker/toolbox/blob/master/LICENSE/LICENSE).