diff --git a/src/OpenMesh/Core/IO/writer/OFFWriter.cc b/src/OpenMesh/Core/IO/writer/OFFWriter.cc
index d6af8114..9f89797d 100644
--- a/src/OpenMesh/Core/IO/writer/OFFWriter.cc
+++ b/src/OpenMesh/Core/IO/writer/OFFWriter.cc
@@ -199,7 +199,7 @@ write_ascii(std::ostream& _out, BaseExporter& _be, Options _opt) const
 
 
   // vertex data (point, normals, colors, texcoords)
-  for (i=0, nV=_be.n_vertices(); i<nV; ++i)
+  for (i=0, nV=int(_be.n_vertices()); i<nV; ++i)
   {
     vh = VertexHandle(i);
     v  = _be.point(vh);
@@ -251,7 +251,7 @@ write_ascii(std::ostream& _out, BaseExporter& _be, Options _opt) const
   // faces (indices starting at 0)
   if (_be.is_triangle_mesh())
   {
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       _be.get_vhandles(FaceHandle(i), vhandles);
       _out << 3 << " ";
@@ -288,7 +288,7 @@ write_ascii(std::ostream& _out, BaseExporter& _be, Options _opt) const
   }
   else
   {
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       nV = _be.get_vhandles(FaceHandle(i), vhandles);
       _out << nV << " ";
@@ -370,7 +370,7 @@ write_binary(std::ostream& _out, BaseExporter& _be, Options _opt) const
   writeValue(_out, 0 );
 
   // vertex data (point, normals, texcoords)
-  for (i=0, nV=_be.n_vertices(); i<nV; ++i)
+  for (i=0, nV=int(_be.n_vertices()); i<nV; ++i)
   {
     vh = VertexHandle(i);
     v  = _be.point(vh);
@@ -419,7 +419,7 @@ write_binary(std::ostream& _out, BaseExporter& _be, Options _opt) const
   // faces (indices starting at 0)
   if (_be.is_triangle_mesh())
   {
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       //face
       _be.get_vhandles(FaceHandle(i), vhandles);
@@ -452,7 +452,7 @@ write_binary(std::ostream& _out, BaseExporter& _be, Options _opt) const
   }
   else
   {
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       //face
       nV = _be.get_vhandles(FaceHandle(i), vhandles);
@@ -538,7 +538,7 @@ binary_size(BaseExporter& _be, Options _opt) const
     unsigned int i, nV, nF;
     std::vector<VertexHandle> vhandles;
 
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       nV = _be.get_vhandles(FaceHandle(i), vhandles);
       data += nV * sizeof(unsigned int);
diff --git a/src/OpenMesh/Core/IO/writer/PLYWriter.cc b/src/OpenMesh/Core/IO/writer/PLYWriter.cc
index 9d54b492..504ec1bd 100644
--- a/src/OpenMesh/Core/IO/writer/PLYWriter.cc
+++ b/src/OpenMesh/Core/IO/writer/PLYWriter.cc
@@ -249,7 +249,7 @@ write_ascii(std::ostream& _out, BaseExporter& _be, Options _opt) const
     _out << std::fixed;
 
   // vertex data (point, normals, colors, texcoords)
-  for (i=0, nV=_be.n_vertices(); i<nV; ++i)
+  for (i=0, nV=int(_be.n_vertices()); i<nV; ++i)
   {
     vh = VertexHandle(i);
     v  = _be.point(vh);
@@ -298,7 +298,7 @@ write_ascii(std::ostream& _out, BaseExporter& _be, Options _opt) const
   // faces (indices starting at 0)
   if (_be.is_triangle_mesh())
   {
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       _be.get_vhandles(FaceHandle(i), vhandles);
       _out << 3 << " ";
@@ -323,7 +323,7 @@ write_ascii(std::ostream& _out, BaseExporter& _be, Options _opt) const
   }
   else
   {
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       nV = _be.get_vhandles(FaceHandle(i), vhandles);
       _out << nV << " ";
@@ -431,7 +431,7 @@ write_binary(std::ostream& _out, BaseExporter& _be, Options _opt) const
   write_header(_out, _be, _opt);
 
   // vertex data (point, normals, texcoords)
-  for (i=0, nV=_be.n_vertices(); i<nV; ++i)
+  for (i=0, nV=int(_be.n_vertices()); i<nV; ++i)
   {
     vh = VertexHandle(i);
     v  = _be.point(vh);
@@ -481,7 +481,7 @@ write_binary(std::ostream& _out, BaseExporter& _be, Options _opt) const
   // faces (indices starting at 0)
   if (_be.is_triangle_mesh())
   {
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       //face
       _be.get_vhandles(FaceHandle(i), vhandles);
@@ -504,7 +504,7 @@ write_binary(std::ostream& _out, BaseExporter& _be, Options _opt) const
   }
   else
   {
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       //face
       nV = _be.get_vhandles(FaceHandle(i), vhandles);
@@ -580,7 +580,7 @@ binary_size(BaseExporter& _be, Options _opt) const
     unsigned int i, nV, nF;
     std::vector<VertexHandle> vhandles;
 
-    for (i=0, nF=_be.n_faces(); i<nF; ++i)
+    for (i=0, nF=int(_be.n_faces()); i<nF; ++i)
     {
       nV = _be.get_vhandles(FaceHandle(i), vhandles);
       data += nV * sizeof(unsigned int);
diff --git a/src/OpenMesh/Core/IO/writer/STLWriter.cc b/src/OpenMesh/Core/IO/writer/STLWriter.cc
index 39d1a74c..741c650d 100644
--- a/src/OpenMesh/Core/IO/writer/STLWriter.cc
+++ b/src/OpenMesh/Core/IO/writer/STLWriter.cc
@@ -152,7 +152,7 @@ write_stla(const std::string& _filename, BaseExporter& _be, Options /* _opt */)
 
 
 
-  unsigned int i, nF(_be.n_faces()), nV;
+  int i, nF(int(_be.n_faces())), nV;
   Vec3f  a, b, c, n;
   std::vector<VertexHandle> vhandles;
   FaceHandle fh;
@@ -205,7 +205,7 @@ write_stla(std::ostream& _out, BaseExporter& _be, Options /* _opt */, std::strea
 {
   omlog() << "[STLWriter] : write ascii file\n";
 
-  unsigned int i, nF(_be.n_faces()), nV;
+  int i, nF(int(_be.n_faces())), nV;
   Vec3f  a, b, c, n;
   std::vector<VertexHandle> vhandles;
   FaceHandle fh;
@@ -265,7 +265,7 @@ write_stlb(const std::string& _filename, BaseExporter& _be, Options /* _opt */)
   }
 
 
-  unsigned int i, nF(_be.n_faces()), nV;
+  int i, nF(int(_be.n_faces())), nV;
   Vec3f  a, b, c, n;
   std::vector<VertexHandle> vhandles;
   FaceHandle fh;
@@ -336,7 +336,7 @@ write_stlb(std::ostream& _out, BaseExporter& _be, Options /* _opt */, std::strea
   omlog() << "[STLWriter] : write binary file\n";
 
 
-  unsigned int i, nF(_be.n_faces()), nV;
+  int i, nF(int(_be.n_faces())), nV;
   Vec3f  a, b, c, n;
   std::vector<VertexHandle> vhandles;
   FaceHandle fh;
@@ -351,7 +351,7 @@ write_stlb(std::ostream& _out, BaseExporter& _be, Options /* _opt */, std::strea
 
 
   // number of faces
-  write_int(_be.n_faces(), _out);
+  write_int(int(_be.n_faces()), _out);
 
 
   // write face set
@@ -413,7 +413,7 @@ binary_size(BaseExporter& _be, Options /* _opt */) const
   bytes += 4;  // #faces
 
 
-  unsigned int i, nF(_be.n_faces());
+  int i, nF(int(_be.n_faces()));
   std::vector<VertexHandle> vhandles;
 
   for (i=0; i<nF; ++i)