diff --git a/Straight_skeleton_2/include/CGAL/create_offset_polygons_2.h b/Straight_skeleton_2/include/CGAL/create_offset_polygons_2.h
index 52cb9c08407..8594a425e4c 100644
--- a/Straight_skeleton_2/include/CGAL/create_offset_polygons_2.h
+++ b/Straight_skeleton_2/include/CGAL/create_offset_polygons_2.h
@@ -55,7 +55,8 @@ create_partial_interior_straight_skeleton_2 ( FT const&     aMaxTime
 
   Cartesian_converter<InputKernel, K> Converter ;
 
-  boost::optional<KFT> lMaxTime( Converter(aMaxTime) ) ;
+  KFT kMaxTime = aMaxTime;
+  boost::optional<KFT> lMaxTime(kMaxTime) ;
 
   SsBuilder ssb( lMaxTime ) ;