diff --git a/Arithmetic_kernel/include/CGAL/BOOST_MP_arithmetic_kernel.h b/Arithmetic_kernel/include/CGAL/BOOST_MP_arithmetic_kernel.h
index 0887fe12f93..330638931eb 100644
--- a/Arithmetic_kernel/include/CGAL/BOOST_MP_arithmetic_kernel.h
+++ b/Arithmetic_kernel/include/CGAL/BOOST_MP_arithmetic_kernel.h
@@ -30,6 +30,7 @@
 
 #include <boost/multiprecision/cpp_int.hpp>
 #ifdef CGAL_USE_GMP
+#include <CGAL/gmp.h>
 #include <boost/multiprecision/gmp.hpp>
 #endif
 
diff --git a/Number_types/include/CGAL/boost_mp.h b/Number_types/include/CGAL/boost_mp.h
index 16330489b33..e2685008029 100644
--- a/Number_types/include/CGAL/boost_mp.h
+++ b/Number_types/include/CGAL/boost_mp.h
@@ -36,6 +36,7 @@
 // ... but we kind of have to :-(
 #include <boost/multiprecision/cpp_int.hpp>
 #ifdef CGAL_USE_GMP
+#include <CGAL/gmp.h>
 #include <boost/multiprecision/gmp.hpp>
 #endif
 
diff --git a/QP_solver/test/QP_solver/master_mps_to_derivatives.cpp b/QP_solver/test/QP_solver/master_mps_to_derivatives.cpp
index 67c43703f89..8d39410d73e 100644
--- a/QP_solver/test/QP_solver/master_mps_to_derivatives.cpp
+++ b/QP_solver/test/QP_solver/master_mps_to_derivatives.cpp
@@ -45,6 +45,7 @@
 # include <boost/multiprecision/cpp_int.hpp>
 // After some CGAL includes so we get a chance to define CGAL_USE_GMP.
 # ifdef CGAL_USE_GMP
+#  include <CGAL/gmp.h>
 #  include <boost/multiprecision/gmp.hpp>
 # endif
 #endif