diff --git a/src/ReinforcementLearningEnvironments/src/environments/3rd_party/gym.jl b/src/ReinforcementLearningEnvironments/src/environments/3rd_party/gym.jl
index cb8038c06..61f01d824 100644
--- a/src/ReinforcementLearningEnvironments/src/environments/3rd_party/gym.jl
+++ b/src/ReinforcementLearningEnvironments/src/environments/3rd_party/gym.jl
@@ -1,12 +1,12 @@
 using .PyCall
 
 function GymEnv(name::String; seed::Union{Int,Nothing}=nothing)
-    if !PyCall.pyexists("gym")
+    if !PyCall.pyexists("gymnasium")
         error(
-            "Cannot import module 'gym'.\n\nIf you did not yet install it, try running\n`ReinforcementLearningEnvironments.install_gym()`\n",
+            "Cannot import module 'gymnasium'.\n\nIf you did not yet install it, try running\n`ReinforcementLearningEnvironments.install_gym()`\n",
         )
     end
-    gym = pyimport_conda("gym", "gym")
+    gym = pyimport_conda("gymnasium", "gymnasium")
     if PyCall.pyexists("d4rl")
         pyimport("d4rl")
     end
@@ -33,7 +33,7 @@ function GymEnv(name::String; seed::Union{Int,Nothing}=nothing)
     elseif obs_space isa Space{<:Dict}
         PyDict
     else
-        error("don't know how to get the observation type from observation space of $obs_space")
+        error("Don't know how to get the observation type from observation space of $obs_space")
     end
     env = GymEnv{obs_type,typeof(act_space),typeof(obs_space),typeof(pyenv)}(
         pyenv,
@@ -69,8 +69,11 @@ RLBase.action_space(env::GymEnv) = env.action_space
 RLBase.state_space(env::GymEnv) = env.observation_space
 
 function RLBase.reward(env::GymEnv{T}) where {T}
-    if pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 4
-        obs, reward, isdone, info = convert(Tuple{T,Float64,Bool,PyDict}, env.state)
+    if pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 5
+        _, reward, = convert(Tuple{T,Float64,Bool,Bool,PyDict}, env.state)
+        reward
+    elseif pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 4
+        _, reward, = convert(Tuple{T,Float64,Bool,PyDict}, env.state)
         reward
     else
         0.0
@@ -78,8 +81,12 @@ function RLBase.reward(env::GymEnv{T}) where {T}
 end
 
 function RLBase.is_terminated(env::GymEnv{T}) where {T}
-    if pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 4
-        obs, reward, isdone, info = convert(Tuple{T,Float64,Bool,PyDict}, env.state)
+    if pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 5
+        _, _, isterminated, istruncated, = convert(Tuple{T,Float64,Bool,Bool,PyDict}, env.state)
+        isterminated || istruncated
+    elseif pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 4
+        @warn "Gym version outdated. Update gym to obtain termination and truncation info instead of done signal."
+        _, _, isdone, = convert(Tuple{T,Float64,Bool,PyDict}, env.state)
         isdone
     else
         false
@@ -87,8 +94,11 @@ function RLBase.is_terminated(env::GymEnv{T}) where {T}
 end
 
 function RLBase.state(env::GymEnv{T}) where {T}
-    if pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 4
-        obs, reward, isdone, info = convert(Tuple{T,Float64,Bool,PyDict}, env.state)
+    if pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 5
+        obs, = convert(Tuple{T,Float64,Bool,Bool,PyDict}, env.state)
+        obs
+    elseif pyisinstance(env.state, PyCall.@pyglobalobj :PyTuple_Type) && length(env.state) == 4
+        obs, = convert(Tuple{T,Float64,Bool,PyDict}, env.state)
         obs
     else
         convert(T, env.state)
@@ -123,19 +133,19 @@ end
 
 function list_gym_env_names(;
     modules=[
-        "gym.envs.algorithmic",
-        "gym.envs.box2d",
-        "gym.envs.classic_control",
-        "gym.envs.mujoco",
-        "gym.envs.mujoco.ant_v3",
-        "gym.envs.mujoco.half_cheetah_v3",
-        "gym.envs.mujoco.hopper_v3",
-        "gym.envs.mujoco.humanoid_v3",
-        "gym.envs.mujoco.swimmer_v3",
-        "gym.envs.mujoco.walker2d_v3",
-        "gym.envs.robotics",
-        "gym.envs.toy_text",
-        "gym.envs.unittest",
+        "gymnasium.envs.algorithmic",
+        "gymnasium.envs.box2d",
+        "gymnasium.envs.classic_control",
+        "gymnasium.envs.mujoco",
+        "gymnasium.envs.mujoco.ant_v3",
+        "gymnasium.envs.mujoco.half_cheetah_v3",
+        "gymnasium.envs.mujoco.hopper_v3",
+        "gymnasium.envs.mujoco.humanoid_v3",
+        "gymnasium.envs.mujoco.swimmer_v3",
+        "gymnasium.envs.mujoco.walker2d_v3",
+        "gymnasium.envs.robotics",
+        "gymnasium.envs.toy_text",
+        "gymnasium.envs.unittest",
         "d4rl.pointmaze",
         "d4rl.hand_manipulation_suite",
         "d4rl.gym_mujoco.gym_envs",
@@ -147,14 +157,14 @@ function list_gym_env_names(;
     if PyCall.pyexists("d4rl")
         pyimport("d4rl")
     end
-    gym = pyimport("gym")
+    gym = pyimport("gymnasium")
     [x.id for x in values(gym.envs.registry) if split(x.entry_point, ':')[1] in modules]
 end
 
 """
-    install_gym(; packages = ["gym", "pybullet"])
+    install_gym(; packages = ["gymnasium", "pybullet"])
 """
-function install_gym(; packages=["gym", "pybullet"])
+function install_gym(; packages=["gymnasium", "pybullet"])
     # Use eventual proxy info
     proxy_arg = String[]
     if haskey(ENV, "http_proxy")
diff --git a/src/ReinforcementLearningEnvironments/test/runtests.jl b/src/ReinforcementLearningEnvironments/test/runtests.jl
index d8dfe872f..59bafe458 100644
--- a/src/ReinforcementLearningEnvironments/test/runtests.jl
+++ b/src/ReinforcementLearningEnvironments/test/runtests.jl
@@ -13,7 +13,7 @@ using OrdinaryDiffEq
 using TimerOutputs
 using Conda
 
-Conda.add("gym")
+Conda.add("gymnasium")
 Conda.add("numpy")
 
 @testset "ReinforcementLearningEnvironments" begin