diff --git a/src/OpenMesh/Apps/QtViewer/QGLViewerWidget.cc b/src/OpenMesh/Apps/QtViewer/QGLViewerWidget.cc
index 817df274..5a589852 100644
--- a/src/OpenMesh/Apps/QtViewer/QGLViewerWidget.cc
+++ b/src/OpenMesh/Apps/QtViewer/QGLViewerWidget.cc
@@ -154,10 +154,10 @@ QGLViewerWidget::~QGLViewerWidget()
 void 
 QGLViewerWidget::setDefaultMaterial(void)
 {
-  GLfloat mat_a[] = {0.1, 0.1, 0.1, 1.0};
-  GLfloat mat_d[] = {0.7, 0.7, 0.5, 1.0};
-  GLfloat mat_s[] = {1.0, 1.0, 1.0, 1.0};
-  GLfloat shine[] = {120.0};
+  GLfloat mat_a[] = {0.1f, 0.1f, 0.1f, 1.0f};
+  GLfloat mat_d[] = {0.7f, 0.7f, 0.5f, 1.0f};
+  GLfloat mat_s[] = {1.0f, 1.0f, 1.0f, 1.0f};
+  GLfloat shine[] = {120.0f};
   
   glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT,   mat_a);
   glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE,   mat_d);
@@ -171,12 +171,12 @@ QGLViewerWidget::setDefaultMaterial(void)
 void
 QGLViewerWidget::setDefaultLight(void)
 {
-  GLfloat pos1[] = { 0.1,  0.1, -0.02, 0.0};
-  GLfloat pos2[] = {-0.1,  0.1, -0.02, 0.0};
-  GLfloat pos3[] = { 0.0,  0.0,  0.1,  0.0};
-  GLfloat col1[] = { 0.7,  0.7,  0.8,  1.0};
-  GLfloat col2[] = { 0.8,  0.7,  0.7,  1.0};
-  GLfloat col3[] = { 1.0,  1.0,  1.0,  1.0};
+  GLfloat pos1[] = { 0.1f,  0.1f, -0.02f, 0.0f};
+  GLfloat pos2[] = {-0.1f,  0.1f, -0.02f, 0.0f};
+  GLfloat pos3[] = { 0.0f,  0.0f,  0.1f,  0.0f};
+  GLfloat col1[] = { 0.7f,  0.7f,  0.8f,  1.0f};
+  GLfloat col2[] = { 0.8f,  0.7f,  0.7f,  1.0f};
+  GLfloat col3[] = { 1.0f,  1.0f,  1.0f,  1.0f};
  
   glEnable(GL_LIGHT0);    
   glLightfv(GL_LIGHT0,GL_POSITION, pos1);
@@ -214,10 +214,10 @@ QGLViewerWidget::initializeGL()
   setDefaultLight();  
   
   // Fog
-  GLfloat fogColor[4] = { 0.3, 0.3, 0.4, 1.0 };
+  GLfloat fogColor[4] = { 0.3f, 0.3f, 0.4f, 1.0f };
   glFogi(GL_FOG_MODE,    GL_LINEAR);
   glFogfv(GL_FOG_COLOR,  fogColor);
-  glFogf(GL_FOG_DENSITY, 0.35);
+  glFogf(GL_FOG_DENSITY, 0.35f);
   glHint(GL_FOG_HINT,    GL_DONT_CARE);
   glFogf(GL_FOG_START,    5.0f);
   glFogf(GL_FOG_END,     25.0f);
diff --git a/src/OpenMesh/Core/IO/reader/PLYReader.cc b/src/OpenMesh/Core/IO/reader/PLYReader.cc
index df42756c..e601ee63 100644
--- a/src/OpenMesh/Core/IO/reader/PLYReader.cc
+++ b/src/OpenMesh/Core/IO/reader/PLYReader.cc
@@ -1077,7 +1077,7 @@ bool _PLYReader_::can_u_read(std::istream& _is) const {
     trim(line);
 
     // Handle '\r\n' newlines 
-    const int s = line.size(); 
+    const size_t s = line.size();
     if( s > 0 && line[s - 1] == '\r') line.resize(s - 1); 
 
     //Check if this file is really a ply format
diff --git a/src/OpenMesh/Tools/Smoother/JacobiLaplaceSmootherT.cc b/src/OpenMesh/Tools/Smoother/JacobiLaplaceSmootherT.cc
index 1d33ff86..c88ac13d 100644
--- a/src/OpenMesh/Tools/Smoother/JacobiLaplaceSmootherT.cc
+++ b/src/OpenMesh/Tools/Smoother/JacobiLaplaceSmootherT.cc
@@ -123,7 +123,7 @@ compute_new_positions_C0()
       u -= vector_cast<typename Mesh::Normal>(Base::mesh_.point(*v_it));
 
       // damping
-      u *= 0.5;
+      u *= static_cast< typename Mesh::Scalar >(0.5);
     
       // store new position
       p  = vector_cast<typename Mesh::Normal>(Base::mesh_.point(*v_it));
diff --git a/src/OpenMesh/Tools/Subdivider/Adaptive/Composite/RulesT.cc b/src/OpenMesh/Tools/Subdivider/Adaptive/Composite/RulesT.cc
index cfea2e98..ba335f6f 100644
--- a/src/OpenMesh/Tools/Subdivider/Adaptive/Composite/RulesT.cc
+++ b/src/OpenMesh/Tools/Subdivider/Adaptive/Composite/RulesT.cc
@@ -863,7 +863,7 @@ void VF<M>::raise(typename M::FaceHandle& _fh, state_t _target_state)
     if (Base::number() == Base::subdiv_rule()->number() + 1 && 
         Base::mesh_.is_boundary(_fh)                  && 
         !MOBJ(_fh).final())
-      position *= 0.5;
+      position *= static_cast<typename M::Scalar>(0.5);
 
     MOBJ(_fh).set_position(_target_state, position);
     MOBJ(_fh).inc_state();
diff --git a/src/OpenMesh/Tools/Subdivider/Uniform/CatmullClarkT.cc b/src/OpenMesh/Tools/Subdivider/Uniform/CatmullClarkT.cc
index b36be58b..ec7a9682 100644
--- a/src/OpenMesh/Tools/Subdivider/Uniform/CatmullClarkT.cc
+++ b/src/OpenMesh/Tools/Subdivider/Uniform/CatmullClarkT.cc
@@ -309,7 +309,7 @@ CatmullClarkT<MeshType,RealType>::compute_midpoint( MeshType& _m, const EdgeHand
   // this yields the [1/2 1/2] mask
   if (_m.is_boundary(_eh) || !_update_points)
   {
-    pos *= 0.5;
+    pos *= static_cast<RealType>(0.5);
   }
 //  else if (_m.status(_eh).selected() )
 //  {
@@ -321,7 +321,7 @@ CatmullClarkT<MeshType,RealType>::compute_midpoint( MeshType& _m, const EdgeHand
   {
     pos += _m.property(fp_pos_, _m.face_handle(heh));
     pos += _m.property(fp_pos_, _m.face_handle(opp_heh));
-    pos *= 0.25;
+    pos *= static_cast<RealType>(0.25);
   }
   _m.property( ep_pos_, _eh ) = pos;
 }
diff --git a/src/Unittests/unittests_smoother.cc b/src/Unittests/unittests_smoother.cc
index 1f95ad40..62848a6b 100644
--- a/src/Unittests/unittests_smoother.cc
+++ b/src/Unittests/unittests_smoother.cc
@@ -111,10 +111,10 @@ TEST_F(OpenMeshSmoother_Poly, Smoother_Triangle_Laplace) {
   OpenMesh::Smoother::JacobiLaplaceSmootherT<PolyMesh> smoother(mesh_);;
 
   // Just call function to instantiate template
-  smoother.set_absolute_local_error(0.5);
+  smoother.set_absolute_local_error(0.5f);
 
   // Set an error
-  smoother.set_relative_local_error(0.1);
+  smoother.set_relative_local_error(0.1f);
 
   // Run algorithm with 5 steps
   smoother.smooth(5);