diff --git a/units/en/unit1/hands-on.mdx b/units/en/unit1/hands-on.mdx
index 9c532aa..3c87f27 100644
--- a/units/en/unit1/hands-on.mdx
+++ b/units/en/unit1/hands-on.mdx
@@ -5,7 +5,7 @@
 
       <CourseFloatingBanner classNames="absolute z-10 right-0 top-0"
       notebooks={[
-        {label: "Google Colab", value: "https://colab.research.google.com/github/huggingface/deep-rl-class/blob/master/notebooks/unit1/unit1.ipynb"}
+        {label: "Google Colab", value: "https://colab.research.google.com/github/huggingface/deep-rl-class/blob/main/notebooks/unit1/unit1.ipynb"}
         ]}
         askForHelpUrl="http://hf.co/join/discord" />
 
diff --git a/units/en/unit2/hands-on.mdx b/units/en/unit2/hands-on.mdx
index 1f226a0..f55cc13 100644
--- a/units/en/unit2/hands-on.mdx
+++ b/units/en/unit2/hands-on.mdx
@@ -2,7 +2,7 @@
 
       <CourseFloatingBanner classNames="absolute z-10 right-0 top-0"
       notebooks={[
-        {label: "Google Colab", value: "https://colab.research.google.com/github/huggingface/deep-rl-class/blob/master/notebooks/unit2/unit2.ipynb"}
+        {label: "Google Colab", value: "https://colab.research.google.com/github/huggingface/deep-rl-class/blob/main/notebooks/unit2/unit2.ipynb"}
         ]}
         askForHelpUrl="http://hf.co/join/discord" />