diff --git a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h
index fbfbd9e3ac1..2540848ed39 100644
--- a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h
+++ b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/dual_contouring_functors.h
@@ -26,7 +26,6 @@
 #include <Eigen/SVD>
 #endif
 
-#include <array>
 #include <map>
 #include <mutex>
 #include <vector>
diff --git a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/marching_cubes_functors.h b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/marching_cubes_functors.h
index a4b846eccc2..232464a923e 100644
--- a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/marching_cubes_functors.h
+++ b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/marching_cubes_functors.h
@@ -55,7 +55,6 @@
 
 #include <array>
 #include <bitset>
-#include <mutex>
 
 namespace CGAL {
 namespace Isosurfacing {
diff --git a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/topologically_correct_marching_cubes_functors.h b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/topologically_correct_marching_cubes_functors.h
index 47f61e3b72a..1c24f226a0f 100644
--- a/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/topologically_correct_marching_cubes_functors.h
+++ b/Isosurfacing_3/include/CGAL/Isosurfacing_3/internal/topologically_correct_marching_cubes_functors.h
@@ -50,12 +50,7 @@
 #include <tbb/concurrent_hash_map.h>
 
 #include <array>
-#include <atomic>
 #include <cmath>
-#include <map>
-#include <mutex>
-#include <atomic>
-#include <optional>
 
 namespace CGAL {
 namespace Isosurfacing {