diff --git a/src/Coordinate.cpp b/src/Coordinate.cpp
index 773f5c43..014e9dfb 100644
--- a/src/Coordinate.cpp
+++ b/src/Coordinate.cpp
@@ -266,10 +266,17 @@ class RoundVisitor : public boost::static_visitor<> {
 
 
     Kernel::FT _roundFT( const Kernel::FT& v ) const {
+        #ifdef CGAL_USE_GMPXX
+        return Kernel::FT( ::mpq_class(
+                               SFCGAL::round( v.exact() * _scaleFactor ),
+                               _scaleFactor
+                           ) ) ;
+        #else
         return Kernel::FT( CGAL::Gmpq(
                                SFCGAL::round( v.exact() * _scaleFactor ),
                                _scaleFactor
                            ) ) ;
+        #endif
     }
 
 };
diff --git a/src/numeric.h b/src/numeric.h
index 0b6f5ed0..6c18818b 100644
--- a/src/numeric.h
+++ b/src/numeric.h
@@ -57,6 +57,20 @@ inline double round( const double& v )
     }
 }
 
+#ifdef CGAL_USE_GMPXX
+/**
+ * @brief floor a rational to an integer
+ */
+SFCGAL_API ::mpz_class floor( const ::mpq_class& v ) ;
+/**
+ * @brief ceil a rational to an integer
+ */
+SFCGAL_API ::mpz_class ceil( const ::mpq_class& v ) ;
+/**
+ * @brief round a rational to an integer
+ */
+SFCGAL_API ::mpz_class round( const ::mpq_class& v ) ;
+#endif
 
 /**
  * @brief floor a rational to an integer