diff --git a/Number_types/include/CGAL/GMP/Gmpq_type.h b/Number_types/include/CGAL/GMP/Gmpq_type.h
index 54776eb5b78..156e24c02ba 100644
--- a/Number_types/include/CGAL/GMP/Gmpq_type.h
+++ b/Number_types/include/CGAL/GMP/Gmpq_type.h
@@ -35,6 +35,10 @@
 #include <CGAL/Handle_for.h>
 #include <CGAL/Profile_counter.h>
 
+#if __cpp_impl_three_way_comparison >= 201907L
+# include <compare>
+#endif
+
 #if defined(BOOST_MSVC)
 #  pragma warning(push)
 #  pragma warning(disable:4146)
@@ -61,8 +65,17 @@ private:
 
 
 class Gmpq
-  : Handle_for<Gmpq_rep>,
-    boost::totally_ordered1< Gmpq
+  : Handle_for<Gmpq_rep>
+#if __cpp_impl_three_way_comparison >= 201907L
+  , boost::field_operators2< Gmpq, int
+  , boost::field_operators2< Gmpq, long
+  , boost::field_operators2< Gmpq, long long
+  , boost::field_operators2< Gmpq, double
+  , boost::field_operators2< Gmpq, Gmpz
+  , boost::field_operators2< Gmpq, Gmpfr
+    > > > > > >
+#else
+  , boost::totally_ordered1< Gmpq
   , boost::ordered_field_operators2< Gmpq, int
   , boost::ordered_field_operators2< Gmpq, long
   , boost::ordered_field_operators2< Gmpq, long long
@@ -70,6 +83,7 @@ class Gmpq
   , boost::ordered_field_operators2< Gmpq, Gmpz
   , boost::ordered_field_operators2< Gmpq, Gmpfr
     > > > > > > >
+#endif
 {
   typedef Handle_for<Gmpq_rep> Base;
 public:
@@ -223,7 +237,11 @@ public:
   Gmpq& operator/=(const Gmpq &q);
 
   bool operator==(const Gmpq &q) const noexcept { return mpq_equal(this->mpq(), q.mpq()) != 0;}
+#if __cpp_impl_three_way_comparison >= 201907L
+  std::strong_ordering operator<=>(const Gmpq&q) const noexcept { return mpq_cmp(this->mpq(), q.mpq()) <=> 0; }
+#else
   bool operator< (const Gmpq &q) const noexcept { return mpq_cmp(this->mpq(), q.mpq()) < 0; }
+#endif
 
   double to_double() const noexcept;
   Sign sign() const noexcept;
@@ -245,54 +263,78 @@ public:
   Gmpq& operator-=(int z){return (*this)-= Gmpq(z);}
   Gmpq& operator*=(int z){return (*this)*= Gmpq(z);}
   Gmpq& operator/=(int z){return (*this)/= Gmpq(z);}
+#if __cpp_impl_three_way_comparison >= 201907L
+  std::strong_ordering operator<=>(int z) const noexcept { return mpq_cmp_si(mpq(),z,1) <=> 0; }
+#else
   bool  operator==(int z) const {return mpq_cmp_si(mpq(),z,1)==0;}
   bool  operator< (int z) const {return mpq_cmp_si(mpq(),z,1)<0;}
   bool  operator> (int z) const {return mpq_cmp_si(mpq(),z,1)>0;}
+#endif
 
   // Interoperability with long
   Gmpq& operator+=(long z){return (*this)+= Gmpq(z);}
   Gmpq& operator-=(long z){return (*this)-= Gmpq(z);}
   Gmpq& operator*=(long z){return (*this)*= Gmpq(z);}
   Gmpq& operator/=(long z){return (*this)/= Gmpq(z);}
+#if __cpp_impl_three_way_comparison >= 201907L
+  std::strong_ordering operator<=>(long z) const noexcept { return mpq_cmp_si(mpq(),z,1) <=> 0; }
+#else
   bool  operator==(long z) const {return mpq_cmp_si(mpq(),z,1)==0;}
   bool  operator< (long z) const {return mpq_cmp_si(mpq(),z,1)<0;}
   bool  operator> (long z) const {return mpq_cmp_si(mpq(),z,1)>0;}
+#endif
 
   // Interoperability with long long
   Gmpq& operator+=(long long z){return (*this)+= Gmpq(z);}
   Gmpq& operator-=(long long z){return (*this)-= Gmpq(z);}
   Gmpq& operator*=(long long z){return (*this)*= Gmpq(z);}
   Gmpq& operator/=(long long z){return (*this)/= Gmpq(z);}
+#if __cpp_impl_three_way_comparison >= 201907L
+  std::strong_ordering operator<=>(long long z) const noexcept { return *this <=> Gmpq(z); }
+#else
   bool  operator==(long long z) const {return (*this)== Gmpq(z);}
   bool  operator< (long long z) const {return (*this)<  Gmpq(z);}
   bool  operator> (long long z) const {return (*this)>  Gmpq(z);}
+#endif
 
   // Interoperability with double
   Gmpq& operator+=(double d){return (*this)+= Gmpq(d);}
   Gmpq& operator-=(double d){return (*this)-= Gmpq(d);}
   Gmpq& operator*=(double d){return (*this)*= Gmpq(d);}
   Gmpq& operator/=(double d){return (*this)/= Gmpq(d);}
+#if __cpp_impl_three_way_comparison >= 201907L
+  std::strong_ordering operator<=>(double d) const noexcept { return *this <=> Gmpq(d); }
+#else
   bool  operator==(double d) const {return (*this)== Gmpq(d);}
   bool  operator< (double d) const {return (*this)<  Gmpq(d);}
   bool  operator> (double d) const {return (*this)>  Gmpq(d);}
+#endif
 
   // Interoperability with Gmpz
   Gmpq& operator+=(const Gmpz&);
   Gmpq& operator-=(const Gmpz&);
   Gmpq& operator*=(const Gmpz&);
   Gmpq& operator/=(const Gmpz&);
+#if __cpp_impl_three_way_comparison >= 201907L
+  std::strong_ordering operator<=>(const Gmpz& z) const noexcept { return *this <=> Gmpq(z); }
+#else
   bool  operator==(const Gmpz &z) const {return (*this)== Gmpq(z);}
   bool  operator< (const Gmpz &z) const {return (*this)<  Gmpq(z);}
   bool  operator> (const Gmpz &z) const {return (*this)>  Gmpq(z);}
+#endif
 
   // Interoperability with Gmpfr
   Gmpq& operator+=(const Gmpfr &f){return (*this)+= Gmpq(f);}
   Gmpq& operator-=(const Gmpfr &f){return (*this)-= Gmpq(f);}
   Gmpq& operator*=(const Gmpfr &f){return (*this)*= Gmpq(f);}
   Gmpq& operator/=(const Gmpfr &f){return (*this)/= Gmpq(f);}
+#if __cpp_impl_three_way_comparison >= 201907L
+  std::strong_ordering operator<=>(const Gmpfr& f) const noexcept { return 0 <=> mpfr_cmp_q(f.fr(),mpq()); }
+#else
   bool  operator==(const Gmpfr &f) const {return mpfr_cmp_q(f.fr(),mpq())==0;}
   bool  operator< (const Gmpfr &f) const {return mpfr_cmp_q(f.fr(),mpq())>0;}
   bool  operator> (const Gmpfr &f) const {return mpfr_cmp_q(f.fr(),mpq())<0;}
+#endif
 };