diff --git a/sources/reactphysics3d/engine/ConstraintSolver.cpp b/sources/reactphysics3d/engine/ConstraintSolver.cpp
index 7f90bd42..0c286d74 100644
--- a/sources/reactphysics3d/engine/ConstraintSolver.cpp
+++ b/sources/reactphysics3d/engine/ConstraintSolver.cpp
@@ -23,6 +23,7 @@
 #include "../body/RigidBody.h"
 
 using namespace reactphysics3d;
+using namespace std;
 
 // Constructor
 ConstraintSolver::ConstraintSolver(PhysicsWorld* world)
@@ -41,7 +42,7 @@ void ConstraintSolver::allocate() {
     Constraint* constraint;
 
     // For each constraint
-    std::vector<Constraint*>::iterator it;
+    vector<Constraint*>::iterator it;
     for (it = physicsWorld->getConstraintsBeginIterator(); it != physicsWorld->getConstraintsEndIterator(); it++) {
         constraint = *it;
 
@@ -57,8 +58,8 @@ void ConstraintSolver::allocate() {
             constraintBodies.insert(constraint->getBody2());
 
             // Fill in the body number maping
-            bodyNumberMapping.insert(std::pair<Body*, unsigned int>(constraint->getBody1(), bodyNumberMapping.size()));
-            bodyNumberMapping.insert(std::pair<Body*, unsigned int>(constraint->getBody2(), bodyNumberMapping.size()));
+            bodyNumberMapping.insert(pair<Body*, unsigned int>(constraint->getBody1(), bodyNumberMapping.size()));
+            bodyNumberMapping.insert(pair<Body*, unsigned int>(constraint->getBody2(), bodyNumberMapping.size()));
 
             // Update the size of the jacobian matrix
             nbConstraints += (1 + constraint->getNbAuxConstraints());
@@ -174,7 +175,7 @@ void ConstraintSolver::fillInMatrices() {
     Vector v(6);
     Vector f(6);
     uint b=0;
-    for (std::set<Body*>::iterator it = constraintBodies.begin(); it != constraintBodies.end(); it++, b++) {
+    for (set<Body*>::iterator it = constraintBodies.begin(); it != constraintBodies.end(); it++, b++) {
         body = *it;
         uint bodyNumber = bodyNumberMapping.at(body);
         
@@ -222,6 +223,7 @@ void ConstraintSolver::freeMemory() {
         delete[] bodyMapping[i];
         delete[] J_sp[i];
     }
+    
     delete[] bodyMapping;
     delete[] J_sp;
     delete[] B_sp[0];
@@ -299,7 +301,7 @@ void ConstraintSolver::updateContactCache() {
         Contact* contact = dynamic_cast<Contact*>(activeConstraints.at(c));
         if (contact) {
             // Create a new ContactCachingInfo
-            ContactCachingInfo contactInfo(contact->getBody1(), contact->getBody2(), contact->getPoint(), lambda.getValue(noConstraint));
+            ContactCachingInfo* contactInfo = new ContactCachingInfo(contact->getBody1(), contact->getBody2(), contact->getPoint(), lambda.getValue(noConstraint));
 
             // Add it to the contact cache
             contactCache.addContactCachingInfo(contactInfo);
diff --git a/sources/reactphysics3d/engine/ContactCache.cpp b/sources/reactphysics3d/engine/ContactCache.cpp
index 8fa3c14e..56c07389 100644
--- a/sources/reactphysics3d/engine/ContactCache.cpp
+++ b/sources/reactphysics3d/engine/ContactCache.cpp
@@ -40,17 +40,17 @@ void ContactCache::clear() {
 }
 
 // Add a new contact caching info in the cache
-void ContactCache::addContactCachingInfo(const ContactCachingInfo& info) {
+void ContactCache::addContactCachingInfo(ContactCachingInfo* info) {
     // Check if there is already an entry for that pair of body in the cache
-    map<pair<Body*, Body*>, vector<ContactCachingInfo> >::iterator entry = cache.find(make_pair(info.body1, info.body2));
+    map<pair<Body*, Body*>, vector<ContactCachingInfo*> >::iterator entry = cache.find(make_pair(info->body1, info->body2));
     if (entry != cache.end()) {
         (*entry).second.push_back(info);
     }
     else {
         // Add a new entry in the cache
-        vector<ContactCachingInfo> vec;
+        vector<ContactCachingInfo*> vec;
         vec.push_back(info);
-        cache.insert(make_pair(make_pair(info.body1, info.body2), vec));
+        cache.insert(make_pair(make_pair(info->body1, info->body2), vec));
     }
 }
 
@@ -59,9 +59,9 @@ void ContactCache::addContactCachingInfo(const ContactCachingInfo& info) {
 // compatible (with approximatively the same position), this method returns NULL.
 ContactCachingInfo* ContactCache::getContactCachingInfo(Body* body1, Body* body2, const Vector3D& position) {
    // Check if there is an entry for that pair of body in the cache
-    map<pair<Body*, Body*>, vector<ContactCachingInfo> >::iterator entry = cache.find(make_pair(body1, body2));
+    map<pair<Body*, Body*>, vector<ContactCachingInfo*> >::iterator entry = cache.find(make_pair(body1, body2));
     if (entry != cache.end()) {
-        vector<ContactCachingInfo> vec = (*entry).second;
+        vector<ContactCachingInfo*> vec = (*entry).second;
         assert((*entry).first.first == body1);
         assert((*entry).first.second == body2);
 
@@ -70,13 +70,13 @@ ContactCachingInfo* ContactCache::getContactCachingInfo(Body* body1, Body* body2
         double posZ = position.getZ();
 
         // Check among all the old contacts for this pair of body if there is an approximative match for the contact position
-        for(vector<ContactCachingInfo>::iterator it = vec.begin(); it != vec.end(); it++) {
-            Vector3D& contactPos = (*it).position;
+        for(vector<ContactCachingInfo*>::iterator it = vec.begin(); it != vec.end(); it++) {
+            Vector3D& contactPos = (*it)->position;
             if (posX <= contactPos.getX() + POSITION_TOLERANCE && posX >= contactPos.getX() - POSITION_TOLERANCE &&
                 posY <= contactPos.getY() + POSITION_TOLERANCE && posY >= contactPos.getY() - POSITION_TOLERANCE &&
                 posZ <= contactPos.getZ() + POSITION_TOLERANCE && posZ >= contactPos.getZ() - POSITION_TOLERANCE) {
                 // Return the ContactCachingInfo
-                return &(*it);
+                return *it;
             }
         }
     }
diff --git a/sources/reactphysics3d/engine/ContactCache.h b/sources/reactphysics3d/engine/ContactCache.h
index 950952cf..5aa38b66 100644
--- a/sources/reactphysics3d/engine/ContactCache.h
+++ b/sources/reactphysics3d/engine/ContactCache.h
@@ -42,14 +42,14 @@ const double POSITION_TOLERANCE = 0.01 ;      // Tolerance used to consider two
 */
 class ContactCache {
     private:
-        std::map<std::pair<Body*, Body*>, std::vector<ContactCachingInfo> > cache;
+        std::map<std::pair<Body*, Body*>, std::vector<ContactCachingInfo*> > cache;
 
     public:
-        ContactCache();                                                                                         // Constructor
-        ~ContactCache();                                                                                        // Destructor
-        void clear();                                                                                           // Remove all the contact caching info of the cache
-        void addContactCachingInfo(const ContactCachingInfo& contactCachingInfo);                               // Add a new contact caching info in the cache
-        ContactCachingInfo* getContactCachingInfo(Body* body1, Body* body2, const Vector3D& position);    // Return the ContactCachingInfo (if exists) corresponding to the arguments
+        ContactCache();                                                                                     // Constructor
+        ~ContactCache();                                                                                    // Destructor
+        void clear();                                                                                       // Remove all the contact caching info of the cache
+        void addContactCachingInfo(ContactCachingInfo* contactCachingInfo);                                 // Add a new contact caching info in the cache
+        ContactCachingInfo* getContactCachingInfo(Body* body1, Body* body2, const Vector3D& position);      // Return the ContactCachingInfo (if exists) corresponding to the arguments
 };
 
 } // End of the ReactPhysics3D namespace