diff --git a/.github/ISSUE_TEMPLATE/2-question.md b/.github/ISSUE_TEMPLATE/2-question.md
index 80af4a5ea9..d3fec8ff17 100644
--- a/.github/ISSUE_TEMPLATE/2-question.md
+++ b/.github/ISSUE_TEMPLATE/2-question.md
@@ -10,7 +10,7 @@ assignees: ''
 <!--
 
 Welcome!  If you have a question you'd like to ask, you can do it here or on the
-mlpack mailing list; see also https://mlpack.org/help.html.
+mlpack mailing list; see also https://www.mlpack.org/questions.html.
 
 If you're looking for how to get involved and contribute, there's no need to
 open an issue---you can see https://www.mlpack.org/community.html instead.
diff --git a/src/mlpack/methods/reinforcement_learning/environment/acrobot.hpp b/src/mlpack/methods/reinforcement_learning/environment/acrobot.hpp
index 74fa70505c..6f23c52b9e 100644
--- a/src/mlpack/methods/reinforcement_learning/environment/acrobot.hpp
+++ b/src/mlpack/methods/reinforcement_learning/environment/acrobot.hpp
@@ -3,7 +3,7 @@
  * @author Rohan Raj
  *
  * This file is an implementation of Acrobot task:
- * https://gym.openai.com/envs/Acrobot-v1/
+ * https://www.gymlibrary.ml/environments/classic_control/acrobot
  *
  * mlpack is free software; you may redistribute it and/or modify it under the
  * terms of the 3-clause BSD license.  You should have received a copy of the
diff --git a/src/mlpack/methods/reinforcement_learning/environment/cart_pole.hpp b/src/mlpack/methods/reinforcement_learning/environment/cart_pole.hpp
index b3fe48d375..3b70838c0f 100644
--- a/src/mlpack/methods/reinforcement_learning/environment/cart_pole.hpp
+++ b/src/mlpack/methods/reinforcement_learning/environment/cart_pole.hpp
@@ -3,7 +3,7 @@
  * @author Shangtong Zhang
  *
  * This file is an implementation of Cart Pole task:
- * https://gym.openai.com/envs/CartPole-v0
+ * https://www.gymlibrary.ml/environments/classic_control/cart_pole
  *
  * TODO: provide an option to use dynamics directly from OpenAI gym.
  *
diff --git a/src/mlpack/methods/reinforcement_learning/environment/continuous_mountain_car.hpp b/src/mlpack/methods/reinforcement_learning/environment/continuous_mountain_car.hpp
index 030ae7675a..9124f521c6 100644
--- a/src/mlpack/methods/reinforcement_learning/environment/continuous_mountain_car.hpp
+++ b/src/mlpack/methods/reinforcement_learning/environment/continuous_mountain_car.hpp
@@ -4,7 +4,7 @@
  * @author Shashank Shekhar
  *
  * This file is an implementation of Continous Mountain Car task:
- * https://gym.openai.com/envs/MountainCarContinuous-v0/
+ * https://www.gymlibrary.ml/environments/classic_control/mountain_car_continuous
  *
  * TODO: provide an option to use dynamics directly from OpenAI gym.
  *
diff --git a/src/mlpack/methods/reinforcement_learning/environment/mountain_car.hpp b/src/mlpack/methods/reinforcement_learning/environment/mountain_car.hpp
index 99ea74eaf1..7bc0d68ca7 100644
--- a/src/mlpack/methods/reinforcement_learning/environment/mountain_car.hpp
+++ b/src/mlpack/methods/reinforcement_learning/environment/mountain_car.hpp
@@ -3,7 +3,7 @@
  * @author Shangtong Zhang
  *
  * This file is an implementation of Mountain Car task:
- * https://gym.openai.com/envs/MountainCar-v0
+ * https://www.gymlibrary.ml/environments/classic_control/mountain_car
  *
  * TODO: provide an option to use dynamics directly from OpenAI gym.
  *
diff --git a/src/mlpack/methods/reinforcement_learning/environment/pendulum.hpp b/src/mlpack/methods/reinforcement_learning/environment/pendulum.hpp
index cb810a33bc..777cccfe21 100644
--- a/src/mlpack/methods/reinforcement_learning/environment/pendulum.hpp
+++ b/src/mlpack/methods/reinforcement_learning/environment/pendulum.hpp
@@ -3,7 +3,7 @@
  * @author Shashank Shekhar
  *
  * This file is an implementation of Pendulum task:
- * https://gym.openai.com/envs/Pendulum-v0/
+ * https://www.gymlibrary.ml/environments/classic_control/pendulum/
  *
  * TODO: provide an option to use dynamics directly from OpenAI gym.
  *