diff --git a/FEM/matrix_routines.cpp b/FEM/matrix_routines.cpp
index 9dfa94611..e1fa51632 100644
--- a/FEM/matrix_routines.cpp
+++ b/FEM/matrix_routines.cpp
@@ -1,6 +1,6 @@
 /**
  * \copyright
- * Copyright (c) 2018, OpenGeoSys Community (http://www.opengeosys.org)
+ * Copyright (c) 2019, OpenGeoSys Community (http://www.opengeosys.org)
  *            Distributed under a Modified BSD License.
  *              See accompanying file LICENSE.txt or
  *              http://www.opengeosys.org/project/license
@@ -3162,6 +3162,7 @@ void M1Vorkond(int aufgabe, double* x, double* b)
                         diag -= dim + 1;
                     } /* i */
                 }     /* Modus iLDU, (zerlegen und) aufloesen */
+            // fall through
         case 3:       /* Linkstransformation des Gesamtsystems x <= L(t)*b */
             if
                 VK_Modus(VK_iLDU)
@@ -3347,7 +3348,7 @@ void M34Vorkond(int aufgabe, double* x, double* b)
             u = 0;
             o = w->usym;
             /* kein break! "Fall through" nach Aufgabe 2 */
-
+            // fall through
         case 2:                    /* Linkstransformation  x <= L*b */
             if (VK_Modus(VK_iLDU)) /* incomplete L(D)U-Zerlegung */
             {
diff --git a/FEM/rf_random_walk.cpp b/FEM/rf_random_walk.cpp
index 92c3a3a94..dbaba24a0 100644
--- a/FEM/rf_random_walk.cpp
+++ b/FEM/rf_random_walk.cpp
@@ -6694,8 +6694,11 @@ void DATWriteParticleVTPFile(int current_time_step)
 
     for (int i = 0; i <= current_time_step; ++i)
     {
-        sprintf(c_dummy, "%i", i);
-        istr = c_dummy;
+        //sprintf(c_dummy, "%i", i);
+        std::ostringstream ss;
+        ss << i;
+        istr = ss.str();
+
         for (std::size_t t = 0; t < time_vector.size(); ++t)
         {
             m_tim = time_vector[t];