diff --git a/sources/reactphysics3d/constraint/Contact.cpp b/sources/reactphysics3d/constraint/Contact.cpp
index 903f47e7..3286984e 100644
--- a/sources/reactphysics3d/constraint/Contact.cpp
+++ b/sources/reactphysics3d/constraint/Contact.cpp
@@ -87,7 +87,10 @@ void Contact::evaluate() {
     upperBound = INFINITY_CONST;
 
     // Compute the error value of the constraint
-    errorValue = -PENETRATION_FACTOR * penetrationDepth;
+    Vector3D velocity1 = rigidBody1->getCurrentBodyState().getLinearVelocity();
+    Vector3D velocity2 = rigidBody2->getCurrentBodyState().getLinearVelocity();
+    double restitutionCoeff = rigidBody1->getRestitution() * rigidBody2->getRestitution();
+    errorValue = restitutionCoeff * (normal.scalarProduct(velocity1) - normal.scalarProduct(velocity2)) + PENETRATION_FACTOR * penetrationDepth; // TODO : Add penetration
 
     // Compute the auxiliary jacobian matrix (this corresponds to the friction constraint)
     Vector3D r1CrossU1 = r1.crossProduct(frictionVectors[0]);
diff --git a/sources/reactphysics3d/constraint/Contact.h b/sources/reactphysics3d/constraint/Contact.h
index 1b4a1a96..6710027a 100644
--- a/sources/reactphysics3d/constraint/Contact.h
+++ b/sources/reactphysics3d/constraint/Contact.h
@@ -29,8 +29,8 @@
 namespace reactphysics3d {
 
 // Constants
-const double FRICTION_COEFFICIENT = 0.2;    // Friction coefficient
-const double PENETRATION_FACTOR = 0.1;      // Penetration factor (between 0 and 1) which specify the importance of the
+const double FRICTION_COEFFICIENT = 0.1;    // Friction coefficient
+const double PENETRATION_FACTOR = 0.6;      // Penetration factor (between 0 and 1) which specify the importance of the
                                             // penetration depth in order to calculate the correct impulse for the contact
 
 /*  -------------------------------------------------------------------