From c696cb0bcb4547e20bf424d266b89b3e166bef18 Mon Sep 17 00:00:00 2001
From: Maximilian Ernestus <maximilian@ernestus.de>
Date: Thu, 30 Nov 2023 14:40:58 +0100
Subject: [PATCH] Clarify in README.md that we switched to gymnasium.

---
 README.md | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index d359871a2..0a0ba9a1a 100644
--- a/README.md
+++ b/README.md
@@ -29,9 +29,11 @@ You can read the latest benchmark results [here](https://imitation.readthedocs.i
 ### Prerequisites
 
 - Python 3.8+
-- (Optional) OpenGL (to render Gym environments)
+- (Optional) OpenGL (to render Gymnasium environments)
 - (Optional) FFmpeg (to encode videos of renders)
 
+> Note: `imitation` is only compatible with newer [gymnasium](https://gymnasium.farama.org/) environment API and does not support the older `gym` API.
+
 ### Installing PyPI release
 
 Installing the PyPI release is the standard way to use `imitation`, and the recommended way for most users.