diff --git a/src/OpenMesh/Core/Utils/RandomNumberGenerator.cc b/src/OpenMesh/Core/Utils/RandomNumberGenerator.cc
index 5e9b3ae8..ef97df73 100644
--- a/src/OpenMesh/Core/Utils/RandomNumberGenerator.cc
+++ b/src/OpenMesh/Core/Utils/RandomNumberGenerator.cc
@@ -63,12 +63,12 @@ namespace OpenMesh {
 
 //== IMPLEMENTATION ===========================================================
 
-RandomNumberGenerator::RandomNumberGenerator(const double _resolution) :
+RandomNumberGenerator::RandomNumberGenerator(const size_t _resolution) :
   resolution_(_resolution),
   iterations_(1),
   maxNum_(RAND_MAX + 1.0)
 {
-  double tmp = resolution_;
+  double tmp = double(resolution_);
   while (tmp > (double(RAND_MAX) + 1.0) ) {
     iterations_++;
     tmp /= (double(RAND_MAX) + 1.0);
@@ -91,7 +91,7 @@ double RandomNumberGenerator::getRand() const {
   return randNum / maxNum_;
 }
 
-double RandomNumberGenerator::resolution() const {
+size_t RandomNumberGenerator::resolution() const {
   return maxNum_;
 }
 
diff --git a/src/OpenMesh/Core/Utils/RandomNumberGenerator.hh b/src/OpenMesh/Core/Utils/RandomNumberGenerator.hh
index 1c69b96a..827e7395 100644
--- a/src/OpenMesh/Core/Utils/RandomNumberGenerator.hh
+++ b/src/OpenMesh/Core/Utils/RandomNumberGenerator.hh
@@ -56,6 +56,8 @@
 
 
 #include <OpenMesh/Core/System/config.h>
+#include <cstdlib>
+
 
 
 //== NAMESPACES ===============================================================
@@ -68,6 +70,7 @@ namespace OpenMesh {
 
 
 /**  Generate a random number between 0.0 and 1.0 with a guaranteed resolution
+ *   ( Number of possible values )
  *
  * Especially useful on windows, as there MAX_RAND is often only 32k which is
  * not enough resolution for a lot of applications
@@ -80,20 +83,20 @@ public:
   *
   * @param _resolution specifies the desired resolution for the random number generated
   */
-  RandomNumberGenerator(const double _resolution);
+  RandomNumberGenerator(const size_t _resolution);
 
   /// returns a random double between 0.0 and 1.0 with a guaranteed resolution
   double getRand() const;
 
-  double resolution() const;
+  size_t resolution() const;
 
 private:
 
   /// desired resolution
-  const double resolution_;
+  const size_t resolution_;
 
   /// number of "blocks" of RAND_MAX that make up the desired _resolution
-  unsigned int iterations_;
+  size_t iterations_;
 
   /// maximum random number generated, which is used for normalization
   double maxNum_;
diff --git a/src/OpenMesh/Tools/VDPM/VHierarchyWindow.cc b/src/OpenMesh/Tools/VDPM/VHierarchyWindow.cc
index cdbf7adc..e6305ad5 100644
--- a/src/OpenMesh/Tools/VDPM/VHierarchyWindow.cc
+++ b/src/OpenMesh/Tools/VDPM/VHierarchyWindow.cc
@@ -116,7 +116,7 @@ update_buffer(VHierarchyNodeHandle _node_handle)
     if (buffer_[none_zero_pos] != 0)  break;
   }
   window_max_ = buffer_min_ + none_zero_pos + 1;
-  for(none_zero_pos=0; none_zero_pos < buffer_size(); ++none_zero_pos)
+  for(none_zero_pos=0; none_zero_pos < int(buffer_size()); ++none_zero_pos)
   {
     if (buffer_[none_zero_pos] != 0)  break;
   }