diff --git a/libsrc/meshing/meshclass.cpp b/libsrc/meshing/meshclass.cpp
index 81d7ead7..356192fc 100644
--- a/libsrc/meshing/meshclass.cpp
+++ b/libsrc/meshing/meshclass.cpp
@@ -5758,8 +5758,8 @@ namespace netgen
       {
         int olds = materials.Size();
         materials.SetSize (domnr);
-        for (int i = olds; i < domnr; i++)
-          materials[i] = 0;
+        for (int i = olds; i < domnr-1; i++)
+          materials[i] = new string("default");
       }
     /*
     materials.Elem(domnr) = new char[strlen(mat)+1];
@@ -5772,7 +5772,7 @@ namespace netgen
   {
     if (domnr <= materials.Size())
       return *materials.Get(domnr);
-    static string emptystring;
+    static string emptystring("default");
     return emptystring;
   }
 
diff --git a/libsrc/meshing/meshclass.hpp b/libsrc/meshing/meshclass.hpp
index 6ec7627a..40d8ebb4 100644
--- a/libsrc/meshing/meshclass.hpp
+++ b/libsrc/meshing/meshclass.hpp
@@ -594,7 +594,10 @@ namespace netgen
     ///
     const string & GetMaterial (int domnr) const;
     const string * GetMaterialPtr (int domnr) const // 1-based
-    { return domnr <= materials.Size() ? materials.Get(domnr) : nullptr; }
+    {
+      static string defaultmat = "default";
+      return domnr <= materials.Size() ? materials.Get(domnr) : &defaultmat;
+    }
     
     DLL_HEADER void SetNBCNames ( int nbcn );