diff --git a/units/en/unit0/introduction.mdx b/units/en/unit0/introduction.mdx
index 0d6bebf..1140683 100644
--- a/units/en/unit0/introduction.mdx
+++ b/units/en/unit0/introduction.mdx
@@ -4,7 +4,7 @@
 
 Welcome to the most fascinating topic in Artificial Intelligence: Deep Reinforcement Learning.
 
-This course will **teach you about Deep Reinforcement Learning from beginner to expert**. It’s completely free.
+This course will **teach you about Deep Reinforcement Learning from beginner to expert**. It’s completely free and open-source!
 
 In this unit you’ll: