diff --git a/trunk/constitutive_j2.f90 b/trunk/constitutive_j2.f90
index 0963c9883..1b88ccd5b 100644
--- a/trunk/constitutive_j2.f90
+++ b/trunk/constitutive_j2.f90
@@ -289,23 +289,32 @@ subroutine constitutive_j2_LpAndItsTangent(Lp,dLp_dTstar,Tstar_v,Temperature,sta
  squarenorm_Tstar = math_mul6x6(Tstar_v,Tstar_v)
  norm_Tstar = dsqrt(squarenorm_Tstar) 
 
-!* Calculation of Lp
- 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
- 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)
-
- dLp_dTstar3333 = 0.0_pReal
+!* Initialization of Lp and dLp_dTstar
+ Lp = 0.0_pReal
  dLp_dTstar = 0.0_pReal
- forall (k=1:3,l=1:3,m=1:3,n=1:3) &
-   dLp_dTstar3333(k,l,m,n) = Tstar33(k,l)*Tstar33(m,n) * (constitutive_j2_n(matID)-1.0_pReal)/squarenorm_Tstar
- forall (k=1:3,l=1:3) &
-   dLp_dTstar3333(k,l,k,l) = dLp_dTstar3333(k,l,k,l) + 1.0_pReal
- dLp_dTstar = math_Plain3333to99(factor * dLp_dTstar3333)
 
+!* for Tstar==0 both Lp and dLp_dTstar are zero (if not n==1)
+ if (norm_Tstar > 0) then
+   !* Calculation of Lp
+   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
+   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)
+   dLp_dTstar3333 = 0.0_pReal
+   forall (k=1:3,l=1:3,m=1:3,n=1:3) &
+		dLp_dTstar3333(k,l,m,n) = Tstar33(k,l)*Tstar33(m,n) * (constitutive_j2_n(matID)-1.0_pReal)/squarenorm_Tstar
+   forall (k=1:3,l=1:3) &
+		dLp_dTstar3333(k,l,k,l) = dLp_dTstar3333(k,l,k,l) + 1.0_pReal
+		dLp_dTstar = math_Plain3333to99(factor * dLp_dTstar3333)
+ end if
+ 
+! if ((ipc==1) .and. (ip==1) .and. (el==1)) then
+!	  write(6,*) 'Lp: ', Lp
+!	  write(6,*) 'dLp_dTstar: ', dLp_dTstar
+! end if
  return
 
 end subroutine