diff --git a/include/hpp/constraints/configuration-constraint.hh b/include/hpp/constraints/configuration-constraint.hh
index 244452a1..cdc6892d 100644
--- a/include/hpp/constraints/configuration-constraint.hh
+++ b/include/hpp/constraints/configuration-constraint.hh
@@ -72,6 +72,7 @@ namespace hpp {
         vector_t weights_;
         EigenBoolVector_t mask_;
         mutable vector_t diff_;
+        mutable Eigen::Matrix<value_type, 1, Eigen::Dynamic> J_;
     }; // class ComBetweenFeet
   } // namespace constraints
 } // namespace hpp
diff --git a/src/configuration-constraint.cc b/src/configuration-constraint.cc
index 7b527ac9..89634b71 100644
--- a/src/configuration-constraint.cc
+++ b/src/configuration-constraint.cc
@@ -80,13 +80,13 @@ namespace hpp {
       matrix_t unused;
 
       LiegroupConstElementRef a (argument, goal_.space());
-      diff_ = goal_ - a;
+      J_ = (goal_ - a).transpose();
 
       // Apply jacobian of the difference on the right.
-      goal_.space()->Jdifference<false> (argument, goal_.vector(), diff_.transpose(), unused);
+      goal_.space()->Jdifference<false> (argument, goal_.vector(), J_, unused);
 
       jacobian.leftCols (robot_->numberDof ()).noalias() =
-        weights_.cwiseProduct(diff_).transpose ();
+        J_.cwiseProduct(weights_.transpose());
     }
   } // namespace constraints
 } // namespace hpp