diff --git a/Mesh_3/include/CGAL/Mesh_3/Worksharing_data_structures.h b/Mesh_3/include/CGAL/Mesh_3/Worksharing_data_structures.h
index a92a4031e9f..7114a5032a1 100644
--- a/Mesh_3/include/CGAL/Mesh_3/Worksharing_data_structures.h
+++ b/Mesh_3/include/CGAL/Mesh_3/Worksharing_data_structures.h
@@ -690,7 +690,7 @@ protected:
 
   }
 
-  const int                         NUM_WORK_ITEMS_PER_BATCH;
+  const size_t                      NUM_WORK_ITEMS_PER_BATCH;
 
   int                               m_num_cells_per_axis;
   int                               m_num_cells;
diff --git a/Triangulation_3/include/CGAL/Delaunay_triangulation_3.h b/Triangulation_3/include/CGAL/Delaunay_triangulation_3.h
index 427bb375010..e9afaef555d 100644
--- a/Triangulation_3/include/CGAL/Delaunay_triangulation_3.h
+++ b/Triangulation_3/include/CGAL/Delaunay_triangulation_3.h
@@ -340,7 +340,7 @@ public:
       }
 #endif // CGAL_CONCURRENT_TRIANGULATION_3_ADD_TEMPORARY_POINTS_ON_FAR_SPHERE
       
-      int i = 0;
+      size_t i = 0;
       // Insert "num_points_seq" points sequentially
       // (or more if dim < 3 after that)
       size_t num_points_seq = (std::min)(num_points, (size_t)100);
diff --git a/Triangulation_3/include/CGAL/Regular_triangulation_3.h b/Triangulation_3/include/CGAL/Regular_triangulation_3.h
index cd47e98642b..948bb757fcd 100644
--- a/Triangulation_3/include/CGAL/Regular_triangulation_3.h
+++ b/Triangulation_3/include/CGAL/Regular_triangulation_3.h
@@ -274,7 +274,7 @@ namespace CGAL {
         }
 #endif // CGAL_CONCURRENT_TRIANGULATION_3_ADD_TEMPORARY_POINTS_ON_FAR_SPHERE
       
-        int i = 0;
+        size_t i = 0;
         // Insert "num_points_seq" points sequentially
         // (or more if dim < 3 after that)
         size_t num_points_seq = (std::min)(num_points, (size_t)500);