diff --git a/trunk/constitutive_j2.f90 b/trunk/constitutive_j2.f90
index da0973507..c17ce019e 100644
--- a/trunk/constitutive_j2.f90
+++ b/trunk/constitutive_j2.f90
@@ -277,21 +277,31 @@ subroutine constitutive_j2_LpAndItsTangent(Lp,dLp_dTstar,Tstar_v,Temperature,sta
  real(pReal) Temperature
  type(p_vec), dimension(homogenization_maxNgrains,mesh_maxNips,mesh_NcpElems) :: state
  real(pReal), dimension(6) :: Tstar_v
+ real(pReal), dimension(3,3) :: Tstar33
  real(pReal), dimension(3,3) :: Lp
  real(pReal), dimension(3,3,3,3) :: dLp_dTstar3333
  real(pReal), dimension(9,9) :: dLp_dTstar
  real(pReal) norm_Tstar
+ real(pReal) factor
  matID = phase_constitutionInstance(material_phase(ipc,ip,el))
 
+ Tstar33 = math_Mandel6to33(Tstar_v)
  norm_Tstar = dsqrt(math_mul6x6(Tstar_v,Tstar_v))
- 
+  
 !* Calculation of Lp
- Lp = math_Mandel6to33(Tstar_v)/norm_Tstar*constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
+ Lp = Tstar33/norm_Tstar*constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
       (dsqrt(1.5_pReal)/constitutive_j2_fTaylor(matID)*norm_Tstar/state(ipc,ip,el)%p(1))**constitutive_j2_n(matID)
 
 !* Calculation of the tangent of Lp
  dLp_dTstar3333 = 0.0_pReal
  dLp_dTstar = 0.0_pReal
+ factor = constitutive_j2_gdot0(matID)/constitutive_j2_fTaylor(matID)* &
+	  (dsqrt(1.5_pReal)/ constitutive_j2_fTaylor(matID)/state(ipc,ip,el)%p(1))**constitutive_j2_n(matID) * &
+		  * norm_Tstar**(constitutive_j2_n(matID)-1.0_pReal)
+ forall (k=1:3,l=1:3,m=1:3,n=1:3) &
+      dLp_dTstar3333(k,l,m,n) = factor * (constitutive_j2_n(matID)-1.0_pReal)/(norm_Tstar**2.0_pReal) * Tstar33(k,l)*Tstar33(m,n)
+ forall (k=1:3,l=1:3) &
+	  dLp_dTstar3333(k,l,k,l) = dLp_dTstar3333(k,l,k,l) + factor
  dLp_dTstar = math_Plain3333to99(dLp_dTstar3333)
 
  return