diff --git a/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/Delaunay_domain_2.h b/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/Delaunay_domain_2.h
index 3d413321261..bb66bd3d577 100644
--- a/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/Delaunay_domain_2.h
+++ b/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/Delaunay_domain_2.h
@@ -224,8 +224,7 @@ namespace Barycentric_coordinates {
     const Point_2& vertex(
       const std::size_t query_index) const {
 
-      CGAL_precondition(
-        query_index >= 0 && query_index < number_of_vertices());
+      CGAL_precondition(query_index < number_of_vertices());
       return m_vhs[query_index]->point();
     }
 
@@ -243,8 +242,7 @@ namespace Barycentric_coordinates {
     bool is_on_boundary(
       const std::size_t query_index) const {
 
-      CGAL_precondition(
-        query_index >= 0 && query_index < number_of_vertices());
+      CGAL_precondition(query_index < number_of_vertices());
       return m_vhs[query_index]->info().is_on_boundary;
     }
 
@@ -267,8 +265,7 @@ namespace Barycentric_coordinates {
       const std::size_t query_index,
       std::vector<std::size_t>& neighbors) const {
 
-      CGAL_precondition(
-        query_index >= 0 && query_index < number_of_vertices());
+      CGAL_precondition(query_index < number_of_vertices());
       const auto vh = m_vhs[query_index];
       neighbors = vh->info().neighbors;
     }
@@ -294,7 +291,7 @@ namespace Barycentric_coordinates {
       triangle.clear();
       const auto fh = m_cdt.locate(query);
       if (fh->is_in_domain()) {
-        for (std::size_t i = 0; i < 3; ++i) {
+        for (int i = 0; i < 3; ++i) {
           triangle.push_back(fh->vertex(i)->info().index);
         }
       }
diff --git a/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/Harmonic_coordinates_2.h b/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/Harmonic_coordinates_2.h
index 0ac2c930ccc..8e7efbd5fc3 100644
--- a/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/Harmonic_coordinates_2.h
+++ b/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/Harmonic_coordinates_2.h
@@ -213,9 +213,9 @@ namespace Barycentric_coordinates {
       const std::size_t i1 = m_element[1];
       const std::size_t i2 = m_element[2];
 
-      CGAL_assertion(i0 >= 0 && i0 < m_domain.number_of_vertices());
-      CGAL_assertion(i1 >= 0 && i1 < m_domain.number_of_vertices());
-      CGAL_assertion(i2 >= 0 && i2 < m_domain.number_of_vertices());
+      CGAL_assertion(i0 < m_domain.number_of_vertices());
+      CGAL_assertion(i1 < m_domain.number_of_vertices());
+      CGAL_assertion(i2 < m_domain.number_of_vertices());
 
       const auto& p0 = m_domain.vertex(i0);
       const auto& p1 = m_domain.vertex(i1);
@@ -276,7 +276,7 @@ namespace Barycentric_coordinates {
       \return an output iterator to the element in the destination range,
       one past the last coordinate stored
 
-      \pre query >= 0 && query < domain.number_of_vertices()
+      \pre query_index >= 0 && query_index < domain.number_of_vertices()
     */
     template<typename OutIterator>
     OutIterator operator()(
@@ -292,7 +292,7 @@ namespace Barycentric_coordinates {
         m_solve_is_called)) return c_begin;
 
       CGAL_precondition(
-        query_index >= 0 && query_index < m_domain.number_of_vertices());
+        query_index < m_domain.number_of_vertices());
       CGAL_assertion(m_boundary.size() > 0);
       CGAL_assertion(m_interior.size() > 0);
 
@@ -597,11 +597,11 @@ namespace Barycentric_coordinates {
               }
             } else {
               triplet_list.push_back(
-                TripletFT(indices[i], indices[idx], w));
+                TripletFT(int(indices[i]), int(indices[idx]), w));
             }
           }
           triplet_list.push_back(
-            TripletFT(indices[i], indices[i], W));
+            TripletFT(int(indices[i]), int(indices[i]), W));
         }
       }
 
diff --git a/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/internal/utils_2.h b/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/internal/utils_2.h
index f92fc180d59..1d740298361 100644
--- a/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/internal/utils_2.h
+++ b/Barycentric_coordinates_2/include/CGAL/Barycentric_coordinates_2/internal/utils_2.h
@@ -364,7 +364,7 @@ namespace internal {
     switch (location) {
 
       case Query_point_location::ON_VERTEX: {
-        CGAL_assertion(index >= 0 && index < n);
+        CGAL_assertion(index < n);
 
         for (std::size_t i = 0; i < n; ++i)
           if (i == index) {
@@ -376,7 +376,7 @@ namespace internal {
       }
 
       case Query_point_location::ON_EDGE: {
-        CGAL_assertion(index >= 0 && index < n);
+        CGAL_assertion(index < n);
 
         if (index == n - 1) {
           return coordinates_on_last_edge_2(