diff --git a/IntroProgrammingInPython.ipynb b/IntroProgrammingInPython.ipynb
index 4f3579c8f221a0018df469e56f500f1a5dd647bf..af32bc4abdab165ac469e267ad41695f8ff12140 100644
--- a/IntroProgrammingInPython.ipynb
+++ b/IntroProgrammingInPython.ipynb
@@ -13,7 +13,8 @@
     "# Introduction to programming in Python\n",
     "\n",
     "Author: Auke Klazema (klazema@astron.nl)\n",
-    "Length: 2.5 days"
+    "Length: 2.5 days\n",
+    "License: [Creative Commons - BY (CC-BY)](https://creativecommons.org/licenses/by/4.0/)"
    ]
   },
   {