diff --git a/gym/envs/mujoco/ant.py b/gym/envs/mujoco/ant.py
index 02c521d0844..866225b1b97 100644
--- a/gym/envs/mujoco/ant.py
+++ b/gym/envs/mujoco/ant.py
@@ -129,4 +129,7 @@ def reset_model(self):
 
     def viewer_setup(self):
         for key, value in DEFAULT_CAMERA_CONFIG.items():
-            setattr(self.viewer.cam, key, value)
+            if isinstance(value, np.ndarray):
+                getattr(self.viewer.cam, key)[:] = value
+            else:
+                setattr(self.viewer.cam, key, value)
diff --git a/gym/envs/mujoco/half_cheetah.py b/gym/envs/mujoco/half_cheetah.py
index 22882ada925..0be8115976b 100644
--- a/gym/envs/mujoco/half_cheetah.py
+++ b/gym/envs/mujoco/half_cheetah.py
@@ -81,4 +81,7 @@ def reset_model(self):
 
     def viewer_setup(self):
         for key, value in DEFAULT_CAMERA_CONFIG.items():
-            setattr(self.viewer.cam, key, value)
+            if isinstance(value, np.ndarray):
+                getattr(self.viewer.cam, key)[:] = value
+            else:
+                setattr(self.viewer.cam, key, value)
diff --git a/gym/envs/mujoco/hopper.py b/gym/envs/mujoco/hopper.py
index 4c0bd2433f1..9c6836b24ec 100644
--- a/gym/envs/mujoco/hopper.py
+++ b/gym/envs/mujoco/hopper.py
@@ -130,4 +130,7 @@ def reset_model(self):
 
     def viewer_setup(self):
         for key, value in DEFAULT_CAMERA_CONFIG.items():
-            setattr(self.viewer.cam, key, value)
+            if isinstance(value, np.ndarray):
+                getattr(self.viewer.cam, key)[:] = value
+            else:
+                setattr(self.viewer.cam, key, value)
diff --git a/gym/envs/mujoco/humanoid.py b/gym/envs/mujoco/humanoid.py
index 033ab56eb6c..7a53b9ebda1 100644
--- a/gym/envs/mujoco/humanoid.py
+++ b/gym/envs/mujoco/humanoid.py
@@ -146,4 +146,7 @@ def reset_model(self):
 
     def viewer_setup(self):
         for key, value in DEFAULT_CAMERA_CONFIG.items():
-            setattr(self.viewer.cam, key, value)
+            if isinstance(value, np.ndarray):
+                getattr(self.viewer.cam, key)[:] = value
+            else:
+                setattr(self.viewer.cam, key, value)
diff --git a/gym/envs/mujoco/swimmer.py b/gym/envs/mujoco/swimmer.py
index f20aeb70a12..4c7f37d003b 100644
--- a/gym/envs/mujoco/swimmer.py
+++ b/gym/envs/mujoco/swimmer.py
@@ -3,6 +3,9 @@
 from gym import utils
 
 
+DEFAULT_CAMERA_CONFIG = {}
+
+
 class SwimmerEnv(mujoco_env.MujocoEnv, utils.EzPickle):
     def __init__(self,
                  forward_reward_weight=1.0,
@@ -75,3 +78,10 @@ def reset_model(self):
 
         observation = self._get_obs()
         return observation
+
+    def viewer_setup(self):
+        for key, value in DEFAULT_CAMERA_CONFIG.items():
+            if isinstance(value, np.ndarray):
+                getattr(self.viewer.cam, key)[:] = value
+            else:
+                setattr(self.viewer.cam, key, value)
diff --git a/gym/envs/mujoco/walker2d.py b/gym/envs/mujoco/walker2d.py
index a7f949c7609..37ebcd7bf77 100644
--- a/gym/envs/mujoco/walker2d.py
+++ b/gym/envs/mujoco/walker2d.py
@@ -122,4 +122,7 @@ def reset_model(self):
 
     def viewer_setup(self):
         for key, value in DEFAULT_CAMERA_CONFIG.items():
-            setattr(self.viewer.cam, key, value)
+            if isinstance(value, np.ndarray):
+                getattr(self.viewer.cam, key)[:] = value
+            else:
+                setattr(self.viewer.cam, key, value)