diff --git a/SimDynamics/DynamicsEngine/BulletEngine/BulletRobot.cpp b/SimDynamics/DynamicsEngine/BulletEngine/BulletRobot.cpp
index 0046edad14f9abfdc7066d3cdbbe49dc99e4d6c4..5f672ea2f6802e2a4795c76f3be256cb5bab6e78 100644
--- a/SimDynamics/DynamicsEngine/BulletEngine/BulletRobot.cpp
+++ b/SimDynamics/DynamicsEngine/BulletEngine/BulletRobot.cpp
@@ -1208,7 +1208,7 @@ Eigen::Vector3f BulletRobot::getComVelocityGlobal( VirtualRobot::RobotNodeSetPtr
 
 Eigen::Vector3f BulletRobot::getLinearMomentumGlobal( VirtualRobot::RobotNodeSetPtr set)
 {
-    boost::recursive_mutex::scoped_lock scoped_lock(*engineMutexPtr);
+    MutexLockPtr lock = getScopedLock();
 	Eigen::Vector3f linMomentum = Eigen::Vector3f::Zero();
 	for (unsigned int i = 0; i < set->getSize(); i++)
 	{
@@ -1224,7 +1224,7 @@ Eigen::Vector3f BulletRobot::getLinearMomentumGlobal( VirtualRobot::RobotNodeSet
 
 Eigen::Vector3f BulletRobot::getAngularMomentumGlobal( VirtualRobot::RobotNodeSetPtr set)
 {
-    boost::recursive_mutex::scoped_lock scoped_lock(*engineMutexPtr);
+    MutexLockPtr lock = getScopedLock();
 	Eigen::Vector3f angMomentum = Eigen::Vector3f::Zero();
 	for (unsigned int i = 0; i < set->getSize(); i++)
 	{