diff --git a/README.md b/README.md
index 276bb0733cb9d361b039f056e73efb30e0baabee..7a4c1ec9e461c111f25bf57a3f76d7fdbd12517a 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,12 @@ Gym is a framework for developing and evaluating reinforcement learning environm
 pip install gym==0.21
 ```
 
+Install also pyglet for the rendering.
+
+```sh
+pip install pyglet==1.5.27
+```
+
 ### Usage
 
 Here is an example of how to use Gym to solve the `CartPole-v1` environment: