diff --git a/dune/gfe/cosseratenergystiffness.hh b/dune/gfe/cosseratenergystiffness.hh
index eeba17e580acbf0a1df4f6c21dfcda9ab8597321..a7b31d83e9003f269b058ba4b431e2946be76e6d 100644
--- a/dune/gfe/cosseratenergystiffness.hh
+++ b/dune/gfe/cosseratenergystiffness.hh
@@ -204,7 +204,7 @@ public:
 
         RT detU = U.determinant();
 
-        return mu_ * sym(UMinus1).frobenius_norm2()
+        return mu_ * sym(UMinus1).frobenius_norm2() + mu_c_ * skew(UMinus1).frobenius_norm2()
                 + (mu_*lambda_)/(2*mu_ + lambda_) * 0.5 * ((detU-1)*(detU-1) + (1.0/detU -1)*(1.0/detU -1));
     }