diff --git a/src/BulletDynamics/Featherstone/btMultiBody.cpp b/src/BulletDynamics/Featherstone/btMultiBody.cpp
index 654f77c09..bdaa47347 100644
--- a/src/BulletDynamics/Featherstone/btMultiBody.cpp
+++ b/src/BulletDynamics/Featherstone/btMultiBody.cpp
@@ -1707,9 +1707,9 @@ void btMultiBody::predictPositionsMultiDof(btScalar dt)
             {
                 //reset to current pos
 
-                for (int i = 0; i < 4; ++i)
+                for (int j = 0; j < 4; ++j)
                 {
-                    pJointPos[i] = m_links[i].m_jointPos[i];
+                    pJointPos[j] = m_links[i].m_jointPos[j];
                 }
                 
                 btVector3 jointVel;
@@ -1725,9 +1725,9 @@ void btMultiBody::predictPositionsMultiDof(btScalar dt)
             }
             case btMultibodyLink::ePlanar:
             {
-                for (int i = 0; i < 3; ++i)
+                for (int j = 0; j < 3; ++j)
                 {
-                    pJointPos[i] = m_links[i].m_jointPos[i];
+                    pJointPos[j] = m_links[i].m_jointPos[j];
                 }
                 pJointPos[0] += dt * getJointVelMultiDof(i)[0];
                 
diff --git a/src/BulletSoftBody/btDeformableBodySolver.cpp b/src/BulletSoftBody/btDeformableBodySolver.cpp
index 03a9be07e..f7a26e01e 100644
--- a/src/BulletSoftBody/btDeformableBodySolver.cpp
+++ b/src/BulletSoftBody/btDeformableBodySolver.cpp
@@ -30,14 +30,9 @@ btDeformableBodySolver::~btDeformableBodySolver()
     delete m_objective;
 }
 
-void btDeformableBodySolver::solveDeformableConstraints(float solverdt)
+void btDeformableBodySolver::solveDeformableConstraints(btScalar solverdt)
 {
     BT_PROFILE("solveConstraints");
-    // save v_{n+1}^* velocity after explicit forces
-//    backupVelocity();
-    
-    // add constraints to the solver
-//    setConstraints();
     m_objective->computeResidual(solverdt, m_residual);
     m_objective->applyDynamicFriction(m_residual);
     computeStep(m_dv, m_residual);
@@ -147,7 +142,7 @@ bool btDeformableBodySolver::updateNodes()
 }
 
 
-void btDeformableBodySolver::predictMotion(float solverdt)
+void btDeformableBodySolver::predictMotion(btScalar solverdt)
 {
     for (int i = 0; i < m_softBodySet.size(); ++i)
     {
diff --git a/src/BulletSoftBody/btDeformableMultiBodyDynamicsWorld.cpp b/src/BulletSoftBody/btDeformableMultiBodyDynamicsWorld.cpp
index 825e7cd66..95f9b48b5 100644
--- a/src/BulletSoftBody/btDeformableMultiBodyDynamicsWorld.cpp
+++ b/src/BulletSoftBody/btDeformableMultiBodyDynamicsWorld.cpp
@@ -196,6 +196,7 @@ void btDeformableMultiBodyDynamicsWorld::solveMultiBodyConstraints()
         btMultiBodyDynamicsWorld::processConstraintsAndDeltaVee();
         m_deformableBodySolver->solveContactConstraints();
     }
+    // todo @xuchenhan: add joint force feedback
 }
 
 void btDeformableMultiBodyDynamicsWorld::addSoftBody(btSoftBody* body, int collisionFilterGroup, int collisionFilterMask)