diff --git a/Code/Source/svFSI/mat_models.cpp b/Code/Source/svFSI/mat_models.cpp
index 6f28fa60..4b706443 100644
--- a/Code/Source/svFSI/mat_models.cpp
+++ b/Code/Source/svFSI/mat_models.cpp
@@ -690,10 +690,10 @@ void get_pk2cc_dev(const ComMod& com_mod, const CepMod& cep_mod, const dmnType&
            2.0*g3*(Es(0,1)*RmRm.slice(3) + Es(0,2)*RmRm.slice(5));
 
       auto CCb = 2.0*ten_dyad_prod(Sb, Sb, nsd);
-      Sb += Sb * r2;
+      Sb = Sb * r2;
 
       // Fiber reinforcement/active stress
-      Sb += Sb + Tfa*mat_dyad_prod(fl.col(0), fl.col(0), nsd);
+      Sb += Tfa*mat_dyad_prod(fl.col(0), fl.col(0), nsd);
 
       double r1 = J2d*mat_ddot(C, Sb, nsd) / nd;
       S = J2d*Sb - r1*Ci;
diff --git a/Code/Source/svFSI/ustruct.cpp b/Code/Source/svFSI/ustruct.cpp
index fb08a2d8..0a57d42f 100644
--- a/Code/Source/svFSI/ustruct.cpp
+++ b/Code/Source/svFSI/ustruct.cpp
@@ -142,7 +142,7 @@ void b_ustruct_3d(const ComMod& com_mod, const int eNoN, const double w, const V
   for (int a = 0; a  < eNoN; a++) {
     NxFi(0,a) = Nx(0,a)*Fi(0,0) + Nx(1,a)*Fi(1,0) + Nx(2,a)*Fi(2,0);
     NxFi(1,a) = Nx(0,a)*Fi(0,1) + Nx(1,a)*Fi(1,1) + Nx(2,a)*Fi(2,1);
-    NxFi(2,a) = Nx(1,a)*Fi(1,2) + Nx(1,a)*Fi(1,2) + Nx(2,a)*Fi(2,2);
+    NxFi(2,a) = Nx(0,a)*Fi(0,2) + Nx(1,a)*Fi(1,2) + Nx(2,a)*Fi(2,2);
   }
 
   nFi(0) = nV(0)*Fi(0,0) + nV(1)*Fi(1,0) + nV(2)*Fi(2,0);
diff --git a/tests/cases/ustruct/LV_Guccione_active/result_001.vtu b/tests/cases/ustruct/LV_Guccione_active/result_001.vtu
index 20dc8af9..6a022183 100644
--- a/tests/cases/ustruct/LV_Guccione_active/result_001.vtu
+++ b/tests/cases/ustruct/LV_Guccione_active/result_001.vtu
@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:e96385b077d909be53eb8db6d7b3fe23a485aa1c7183af28920474128126f622
-size 71817
+oid sha256:9a063d96839c465428d82ffc4638c16feb3a33d9ee49422353b5f300f5b79479
+size 45994