diff --git a/xcsg/clipper_csg/clipper_profile.cpp b/xcsg/clipper_csg/clipper_profile.cpp
index 3341466..f56e3ad 100644
--- a/xcsg/clipper_csg/clipper_profile.cpp
+++ b/xcsg/clipper_csg/clipper_profile.cpp
@@ -34,6 +34,11 @@ void clipper_profile::AddPaths(std::shared_ptr<ClipperLib::Paths> paths)
    }
 }
 
+void clipper_profile::AddPath(const ClipperLib::Path& path)
+{
+   m_paths.push_back(path);
+}
+
 std::shared_ptr<polyset2d> clipper_profile::polyset()
 {
    std::shared_ptr<polyset2d> pset(new polyset2d());
@@ -53,17 +58,14 @@ std::shared_ptr<polyset2d> clipper_profile::polyset()
    return pset;
 }
 
-
-void clipper_profile::fill_holes()
+void clipper_profile::positive_profiles(std::list<std::shared_ptr<clipper_profile>>& profiles )
 {
-   // to fill the holes, we simply discard the negative paths
-   ClipperLib::Paths filled_paths;
-   filled_paths.reserve(m_paths.size());
    for(size_t i=0; i<m_paths.size(); i++) {
       bool positive = Orientation(m_paths[i]);
       if(positive) {
-         filled_paths.push_back(m_paths[i]);
+         std::shared_ptr<clipper_profile> prof = std::make_shared<clipper_profile>();
+         prof->AddPath(m_paths[i]);
+         profiles.push_back(prof);
       }
    }
-   m_paths = filled_paths;
 }
diff --git a/xcsg/clipper_csg/clipper_profile.h b/xcsg/clipper_csg/clipper_profile.h
index 09851e9..e7e38de 100644
--- a/xcsg/clipper_csg/clipper_profile.h
+++ b/xcsg/clipper_csg/clipper_profile.h
@@ -19,6 +19,7 @@
 #include "clipper_csg_config.h"
 #include "clipper.hpp"
 #include "polyset2d.h"
+#include <list>
 
 // A clipper_profile represents the result of successive 2d booleans
 // It can represent any complex 2d profile, possibly multiple polygons with holes.
@@ -37,8 +38,12 @@ class clipper_profile {
    // return a set of polygons for this profile
    std::shared_ptr<polyset2d> polyset();
 
-   // fill holes in this profile
-   void fill_holes();
+   // split this profile into a number of single contour profiles containing only positive winding order paths
+   // negative winding order paths are discareded
+   void positive_profiles(std::list<std::shared_ptr<clipper_profile>>& profiles );
+
+protected:
+   void AddPath(  const ClipperLib::Path& path);
 
 private:
    ClipperLib::Paths m_paths;
diff --git a/xcsg/xcsg_factory.cpp b/xcsg/xcsg_factory.cpp
index 95af4ba..3b63c7f 100644
--- a/xcsg/xcsg_factory.cpp
+++ b/xcsg/xcsg_factory.cpp
@@ -70,7 +70,7 @@ xcsg_factory::xcsg_factory()
    m_shape2d_map.insert(std::make_pair("intersection2d",xcsg_factory::make_intersection2d));
    m_shape2d_map.insert(std::make_pair("union2d",xcsg_factory::make_union2d));
    m_shape2d_map.insert(std::make_pair("hull2d",xcsg_factory::make_hull2d));
-   m_shape2d_map.insert(std::make_pair("fill2d",xcsg_factory::make_hull2d));
+   m_shape2d_map.insert(std::make_pair("fill2d",xcsg_factory::make_fill2d));
    m_shape2d_map.insert(std::make_pair("offset2d",xcsg_factory::make_offset2d));
 }
 
diff --git a/xcsg/xfill2d.cpp b/xcsg/xfill2d.cpp
index 343eb94..128041a 100644
--- a/xcsg/xfill2d.cpp
+++ b/xcsg/xfill2d.cpp
@@ -48,8 +48,16 @@ std::shared_ptr<clipper_profile> xfill2d ::create_clipper_profile(const carve::m
    clipper_boolean csg;
    for(auto i=m_incl.begin(); i!=m_incl.end(); i++) {
       std::shared_ptr<clipper_profile> profile = (*i)->create_clipper_profile(t*get_transform());
-      profile->fill_holes();
-      csg.compute(profile,ClipperLib::ctUnion);
+
+      // split the profile into single path profiles with only positive winding order
+      std::list<std::shared_ptr<clipper_profile>> profiles;
+      profile->positive_profiles(profiles);
+
+      // union the profiles to obtain a single profile again
+      // the effect is that all holes dissapear, but outer contours remain
+      for(auto& p : profiles) {
+         csg.compute(p,ClipperLib::ctUnion);
+      }
    }
    return csg.profile();
 }