diff --git a/include/random_plugin.hh b/include/random_plugin.hh
index 1c33fae..a91ab7e 100644
--- a/include/random_plugin.hh
+++ b/include/random_plugin.hh
@@ -18,7 +18,7 @@ class RNG_plugin
     }
     virtual ~RNG_plugin() {}
     virtual bool isMultiscale() const = 0;
-    virtual void Fill_Grid( Grid_FFT<real_t>& g ) const = 0;
+    virtual void Fill_Grid( Grid_FFT<real_t>& g ) = 0;//const = 0;
     //virtual void FillGrid(int level, DensityGrid<real_t> &R) = 0;
 };
 
diff --git a/src/plugins/random_music.cc b/src/plugins/random_music.cc
index ab0f959..28486b5 100644
--- a/src/plugins/random_music.cc
+++ b/src/plugins/random_music.cc
@@ -40,7 +40,7 @@ public:
 
   bool isMultiscale() const { return true; }
 
-  void Fill_Grid( Grid_FFT<real_t>& g ) const { }
+  void Fill_Grid( Grid_FFT<real_t>& g ) {} //const { }
 
   void initialize_for_grid_structure()//const refinement_hierarchy &refh)
   {
diff --git a/src/plugins/random_ngenic.cc b/src/plugins/random_ngenic.cc
index f1c6a59..1498d4b 100644
--- a/src/plugins/random_ngenic.cc
+++ b/src/plugins/random_ngenic.cc
@@ -63,7 +63,7 @@ public:
 
     bool isMultiscale() const { return false; }
 
-    void Fill_Grid(Grid_FFT<real_t> &g) const
+    void Fill_Grid(Grid_FFT<real_t> &g) //const
     {
         g.zero();
         g.FourierTransformForward(false);