diff --git a/examples/pybullet/gym/pybullet_envs/__init__.py b/examples/pybullet/gym/pybullet_envs/__init__.py
index c8764cd59..d4c81d0a7 100644
--- a/examples/pybullet/gym/pybullet_envs/__init__.py
+++ b/examples/pybullet/gym/pybullet_envs/__init__.py
@@ -1,4 +1,10 @@
-from gym.envs.registration import registry, register, make, spec
+import gym
+from gym.envs.registration import registry, make, spec
+def register(id,*args,**kvargs):
+	if id in  registry.env_specs:
+		return
+	else:
+		return gym.envs.registration.register(id,*args,**kvargs)
 
 # ------------bullet-------------
 
diff --git a/examples/pybullet/gym/pybullet_envs/bullet/kukaGymEnv.py b/examples/pybullet/gym/pybullet_envs/bullet/kukaGymEnv.py
index d2a47935d..b9ef16017 100644
--- a/examples/pybullet/gym/pybullet_envs/bullet/kukaGymEnv.py
+++ b/examples/pybullet/gym/pybullet_envs/bullet/kukaGymEnv.py
@@ -275,3 +275,11 @@ class KukaGymEnv(gym.Env):
      #print("reward")
     #print(reward)
     return reward
+
+    def reset(self):
+        """Resets the state of the environment and returns an initial observation.
+
+        Returns: observation (object): the initial observation of the
+            space.
+        """
+        return self._reset()
\ No newline at end of file
diff --git a/examples/pybullet/gym/pybullet_envs/gym_manipulator_envs.py b/examples/pybullet/gym/pybullet_envs/gym_manipulator_envs.py
index 52026925e..2fbf1fdd7 100644
--- a/examples/pybullet/gym/pybullet_envs/gym_manipulator_envs.py
+++ b/examples/pybullet/gym/pybullet_envs/gym_manipulator_envs.py
@@ -41,7 +41,7 @@ class ReacherBulletEnv(MJCFBaseBulletEnv):
 class PusherBulletEnv(MJCFBaseBulletEnv):
 	def __init__(self):
 		self.robot = Pusher()
-		BaseBulletEnv.__init__(self, self.robot)
+		MJCFBaseBulletEnv.__init__(self, self.robot)
 
 	def create_single_player_scene(self):
 		return SingleRobotEmptyScene(gravity=9.81, timestep=0.0020, frame_skip=5)
@@ -95,7 +95,7 @@ class PusherBulletEnv(MJCFBaseBulletEnv):
 class StrikerBulletEnv(MJCFBaseBulletEnv):
 	def __init__(self):
 		self.robot = Striker()
-		BaseBulletEnv.__init__(self, self.robot)
+		MJCFBaseBulletEnv.__init__(self, self.robot)
 		self._striked = False
 		self._min_strike_dist = np.inf
 		self.strike_threshold = 0.1
@@ -171,7 +171,7 @@ class StrikerBulletEnv(MJCFBaseBulletEnv):
 class ThrowerBulletEnv(MJCFBaseBulletEnv):
 	def __init__(self):
 		self.robot = Thrower()
-		BaseBulletEnv.__init__(self, self.robot)
+		MJCFBaseBulletEnv.__init__(self, self.robot)
 
 	def create_single_player_scene(self):
 		return SingleRobotEmptyScene(gravity=0.0, timestep=0.0020, frame_skip=5)
diff --git a/src/BulletCollision/CollisionDispatch/btSimulationIslandManager.cpp b/src/BulletCollision/CollisionDispatch/btSimulationIslandManager.cpp
index f849e31e3..91c76a8da 100644
--- a/src/BulletCollision/CollisionDispatch/btSimulationIslandManager.cpp
+++ b/src/BulletCollision/CollisionDispatch/btSimulationIslandManager.cpp
@@ -261,13 +261,11 @@ void btSimulationIslandManager::buildIslands(btDispatcher* dispatcher,btCollisio
 			btAssert((colObj0->getIslandTag() == islandId) || (colObj0->getIslandTag() == -1));
 			if (colObj0->getIslandTag() == islandId)
 			{
-				if (colObj0->getActivationState()== ACTIVE_TAG)
-				{
-					allSleeping = false;
-				}
-				if (colObj0->getActivationState()== DISABLE_DEACTIVATION)
+				if (colObj0->getActivationState()== ACTIVE_TAG ||
+				   colObj0->getActivationState()== DISABLE_DEACTIVATION)
 				{
 					allSleeping = false;
+					break;
 				}
 			}
 		}
diff --git a/src/BulletCollision/CollisionShapes/btCapsuleShape.h b/src/BulletCollision/CollisionShapes/btCapsuleShape.h
index 7d64b46ab..5a3362834 100644
--- a/src/BulletCollision/CollisionShapes/btCapsuleShape.h
+++ b/src/BulletCollision/CollisionShapes/btCapsuleShape.h
@@ -49,6 +49,7 @@ public:
 	virtual void setMargin(btScalar collisionMargin)
 	{
 		//don't override the margin for capsules, their entire radius == margin
+		(void)collisionMargin;
 	}
 
 	virtual void getAabb (const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const
diff --git a/src/BulletDynamics/Dynamics/btSimulationIslandManagerMt.cpp b/src/BulletDynamics/Dynamics/btSimulationIslandManagerMt.cpp
index 99b34353c..65e1a140e 100644
--- a/src/BulletDynamics/Dynamics/btSimulationIslandManagerMt.cpp
+++ b/src/BulletDynamics/Dynamics/btSimulationIslandManagerMt.cpp
@@ -314,13 +314,11 @@ void btSimulationIslandManagerMt::buildIslands( btDispatcher* dispatcher, btColl
 			btAssert((colObj0->getIslandTag() == islandId) || (colObj0->getIslandTag() == -1));
 			if (colObj0->getIslandTag() == islandId)
 			{
-				if (colObj0->getActivationState()== ACTIVE_TAG)
-				{
-					allSleeping = false;
-				}
-				if (colObj0->getActivationState()== DISABLE_DEACTIVATION)
+				if (colObj0->getActivationState()== ACTIVE_TAG ||
+				   colObj0->getActivationState()== DISABLE_DEACTIVATION)
 				{
 					allSleeping = false;
+					break;
 				}
 			}
 		}
diff --git a/src/LinearMath/btThreads.h b/src/LinearMath/btThreads.h
index 05fd15ec8..cef542329 100644
--- a/src/LinearMath/btThreads.h
+++ b/src/LinearMath/btThreads.h
@@ -72,6 +72,8 @@ SIMD_FORCE_INLINE void btMutexLock( btSpinMutex* mutex )
 {
 #if BT_THREADSAFE
     mutex->lock();
+#else
+    (void)mutex;
 #endif // #if BT_THREADSAFE
 }
 
@@ -79,6 +81,8 @@ SIMD_FORCE_INLINE void btMutexUnlock( btSpinMutex* mutex )
 {
 #if BT_THREADSAFE
     mutex->unlock();
+#else
+    (void)mutex;
 #endif // #if BT_THREADSAFE
 }
 
@@ -87,6 +91,7 @@ SIMD_FORCE_INLINE bool btMutexTryLock( btSpinMutex* mutex )
 #if BT_THREADSAFE
     return mutex->tryLock();
 #else
+    (void)mutex;
     return true;
 #endif // #if BT_THREADSAFE
 }