diff --git a/a2c_ppo_acktr/envs.py b/a2c_ppo_acktr/envs.py
index ffd65d64a..cc502324f 100755
--- a/a2c_ppo_acktr/envs.py
+++ b/a2c_ppo_acktr/envs.py
@@ -201,7 +201,7 @@ def _obfilt(self, obs, update=True):
                 self.obs_rms.update(obs)
             obs = np.clip((obs - self.obs_rms.mean) /
                           np.sqrt(self.obs_rms.var + self.epsilon),
-                          -self.clipob, self.clipob)
+                          -self.clip_obs, self.clip_obs)
             return obs
         else:
             return obs