diff --git a/tonic/environments/__init__.py b/tonic/environments/__init__.py
index b375932c..c0f6afb4 100644
--- a/tonic/environments/__init__.py
+++ b/tonic/environments/__init__.py
@@ -1,8 +1,8 @@
-from .builders import Bullet, ControlSuite, Gym
+from .builders import Bullet, ControlSuite, Gym, Unity
 from .distributed import distribute, Parallel, Sequential
 from .wrappers import ActionRescaler, TimeFeature
 
 
 __all__ = [
-    Bullet, ControlSuite, Gym, distribute, Parallel, Sequential,
+    Bullet, ControlSuite, Gym, Unity, distribute, Parallel, Sequential,
     ActionRescaler, TimeFeature]
diff --git a/tonic/environments/builders.py b/tonic/environments/builders.py
index 3adec879..b9cbca0d 100644
--- a/tonic/environments/builders.py
+++ b/tonic/environments/builders.py
@@ -9,6 +9,8 @@
 from tonic.utils import logger
 
 
+worker_index = 0
+
 def gym_environment(*args, **kwargs):
     '''Returns a wrapped Gym environment.'''
 
@@ -17,6 +19,32 @@ def _builder(*args, **kwargs):
 
     return build_environment(_builder, *args, **kwargs)
 
+def unity_environment(*args, **kwargs):
+    '''Returns a wrapped Unity environment.'''
+    from gym_unity.envs import UnityToGymWrapper
+    from mlagents_envs.environment import UnityEnvironment
+    from mlagents_envs.exception import UnityWorkerInUseException
+    def _builder(name, start_id, *args, **kwargs):
+        # Try connecting to the Unity3D game instance.
+        global worker_index
+        worker_index = int(start_id)
+        while True:
+            try:
+                unity_env = UnityEnvironment(name,
+                                no_graphics=True,
+                                worker_id=worker_index)
+            except UnityWorkerInUseException:
+                import random
+                worker_index += random.randint(0, 1000)
+            else:
+                break
+
+        print("worker_index", worker_index, flush=True)
+        environment = UnityToGymWrapper(unity_env)
+        time_limit = int(1000)  # The time limit is not yet visible from the env
+        return gym.wrappers.TimeLimit(environment, time_limit)
+
+    return build_environment(_builder, *args, **kwargs)
 
 def bullet_environment(*args, **kwargs):
     '''Returns a wrapped PyBullet environment.'''
@@ -160,3 +188,4 @@ def render(self, mode='rgb_array', height=None, width=None, camera_id=0):
 Gym = gym_environment
 Bullet = bullet_environment
 ControlSuite = control_suite_environment
+Unity = unity_environment
diff --git a/tonic/environments/distributed.py b/tonic/environments/distributed.py
index 3d9f4f1f..42f7158d 100644
--- a/tonic/environments/distributed.py
+++ b/tonic/environments/distributed.py
@@ -1,7 +1,6 @@
 '''Builders for distributed training.'''
 
 import multiprocessing
-
 import numpy as np
 
 
@@ -97,6 +96,7 @@ def proc(action_pipe, index, seed):
         dummy_environment = self.environment_builder()
         self.observation_space = dummy_environment.observation_space
         self.action_space = dummy_environment.action_space
+        dummy_environment.close()
         del dummy_environment
         self.started = False
 
@@ -159,6 +159,7 @@ def distribute(environment_builder, worker_groups=1, workers_per_group=1):
     '''Distributes workers over parallel and sequential groups.'''
     dummy_environment = environment_builder()
     max_episode_steps = dummy_environment.max_episode_steps
+    dummy_environment.close()
     del dummy_environment
 
     if worker_groups < 2: