diff --git a/README.md b/README.md
index 6c8bd9e..244f524 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # presentations
 
+The content in all the presentations in this repo are licensed under [CC-BY 4.0](http://creativecommons.org/licenses/by-sa/4.0/). Some images are from [unDraw](https://undraw.co/illustrations/). Here's a link to their *very* [permissive license](https://undraw.co/license).
+<a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-sa/4.0/88x31.png" /></a>