diff --git a/ml5/2_6_1_Q-Learning_Basic.ipynb b/ml5/2_6_1_Q-Learning_Basic.ipynb
index dd174f9..8a8f5e1 100644
--- a/ml5/2_6_1_Q-Learning_Basic.ipynb
+++ b/ml5/2_6_1_Q-Learning_Basic.ipynb
@@ -44,7 +44,7 @@
     "First of all, install the Gymnasium library, which is a fork of the OpenAI Gym  library:\n",
     "\n",
     "```console\n",
-    "foo@bar:~$ conda install gymnasium\n",
+    "foo@bar:~$ pip install gymnasium[classic-control]\n",
     "```\n",
     "\n",
     "If you get an error 'No module named 'Box2D', install 'pybox2d'.\n"