diff --git a/AMDiS/src/parallel/PetscSolverGlobalMatrix.cc b/AMDiS/src/parallel/PetscSolverGlobalMatrix.cc
index 0bf7c516ee113bb3cac828d7bcd0e3424808dc9d..bacbef5861d7fbfac5b31da1c977cad45ab2c354 100644
--- a/AMDiS/src/parallel/PetscSolverGlobalMatrix.cc
+++ b/AMDiS/src/parallel/PetscSolverGlobalMatrix.cc
@@ -94,6 +94,20 @@ namespace AMDiS {
     MatAssemblyBegin(petscMatrix, MAT_FINAL_ASSEMBLY);
     MatAssemblyEnd(petscMatrix, MAT_FINAL_ASSEMBLY);
 
+    // === Init PETSc solver. ===
+    KSPCreate(PETSC_COMM_WORLD, &solver);
+    KSPGetPC(solver, &pc);
+    KSPSetOperators(solver, petscMatrix, petscMatrix, SAME_NONZERO_PATTERN); 
+    KSPSetTolerances(solver, 0.0, 1e-8, PETSC_DEFAULT, PETSC_DEFAULT);
+    KSPSetType(solver, KSPBCGS);
+    KSPMonitorSet(solver, myKSPMonitor, PETSC_NULL, 0);
+    KSPSetFromOptions(solver);
+    PCSetFromOptions(pc);
+
+    // Do not delete the solution vector, use it for the initial guess.
+    if (!zeroStartVector)
+      KSPSetInitialGuessNonzero(solver, PETSC_TRUE);
+
     MSG("Fill petsc matrix needed %.5f seconds\n", MPI::Wtime() - wtime);
   }
 
@@ -138,20 +152,6 @@ namespace AMDiS {
       VecAssemblyEnd(petscSolVec);
     }
 
-    // === Init PETSc solver. ===
-    KSPCreate(PETSC_COMM_WORLD, &solver);
-    KSPGetPC(solver, &pc);
-    KSPSetOperators(solver, petscMatrix, petscMatrix, SAME_NONZERO_PATTERN); 
-    KSPSetTolerances(solver, 0.0, 1e-8, PETSC_DEFAULT, PETSC_DEFAULT);
-    KSPSetType(solver, KSPBCGS);
-    KSPMonitorSet(solver, myKSPMonitor, PETSC_NULL, 0);
-    KSPSetFromOptions(solver);
-    PCSetFromOptions(pc);
-
-    // Do not delete the solution vector, use it for the initial guess.
-    if (!zeroStartVector)
-      KSPSetInitialGuessNonzero(solver, PETSC_TRUE);
-
     // PETSc.
     KSPSolve(solver, petscRhsVec, petscSolVec);
 
@@ -182,17 +182,27 @@ namespace AMDiS {
     // === Destroy PETSc's variables. ===
 
 #ifdef HAVE_PETSC_DEV 
-    MatDestroy(&petscMatrix);
     VecDestroy(&petscRhsVec);
+#else
+    VecDestroy(petscRhsVec);
+#endif
+  }
+
+
+  void PetscSolverGlobalMatrix::destroyMatrixData()
+  {
+    FUNCNAME("PetscSolverGlobalMatrix::destroyMatrixData()");
+
+#ifdef HAVE_PETSC_DEV 
+    MatDestroy(&petscMatrix);
+    KSPDestroy(&solver);
     VecDestroy(&petscSolVec);
     VecDestroy(&petscTmpVec);
-    KSPDestroy(&solver);
 #else
     MatDestroy(petscMatrix);
-    VecDestroy(petscRhsVec);
+    KSPDestroy(solver);
     VecDestroy(petscSolVec);
     VecDestroy(petscTmpVec);
-    KSPDestroy(solver);
 #endif
   }
 
diff --git a/AMDiS/src/parallel/PetscSolverGlobalMatrix.h b/AMDiS/src/parallel/PetscSolverGlobalMatrix.h
index 34bc9af1ba7962699ecfbcee4a9d23dfe9cb6d63..252b27615a370727ac23adf2340324035decdc0d 100644
--- a/AMDiS/src/parallel/PetscSolverGlobalMatrix.h
+++ b/AMDiS/src/parallel/PetscSolverGlobalMatrix.h
@@ -50,8 +50,7 @@ namespace AMDiS {
 
     void solvePetscMatrix(SystemVector &vec, AdaptInfo *adaptInfo);    
 
-    void destroyMatrixData()
-    {}
+    void destroyMatrixData();
 
   protected:
     /// Creates a new non zero pattern structure for the PETSc matrix.