diff --git a/src/libslic3r/Polyline.cpp b/src/libslic3r/Polyline.cpp
index a6be64299..68c40fc20 100644
--- a/src/libslic3r/Polyline.cpp
+++ b/src/libslic3r/Polyline.cpp
@@ -120,7 +120,8 @@ void Polyline::simplify(double tolerance)
     this->points = MultiPoint::_douglas_peucker(this->points, tolerance);
 }
 
-/* This method simplifies all *lines* contained in the supplied area */
+#if 0
+// This method simplifies all *lines* contained in the supplied area
 template <class T>
 void Polyline::simplify_by_visibility(const T &area)
 {
@@ -141,6 +142,7 @@ void Polyline::simplify_by_visibility(const T &area)
 }
 template void Polyline::simplify_by_visibility<ExPolygon>(const ExPolygon &area);
 template void Polyline::simplify_by_visibility<ExPolygonCollection>(const ExPolygonCollection &area);
+#endif
 
 void Polyline::split_at(const Point &point, Polyline* p1, Polyline* p2) const
 {
diff --git a/src/libslic3r/Polyline.hpp b/src/libslic3r/Polyline.hpp
index 51dcf9d36..758fc38cd 100644
--- a/src/libslic3r/Polyline.hpp
+++ b/src/libslic3r/Polyline.hpp
@@ -72,7 +72,7 @@ public:
     void extend_start(double distance);
     Points equally_spaced_points(double distance) const;
     void simplify(double tolerance);
-    template <class T> void simplify_by_visibility(const T &area);
+//    template <class T> void simplify_by_visibility(const T &area);
     void split_at(const Point &point, Polyline* p1, Polyline* p2) const;
     bool is_straight() const;
     bool is_closed() const { return this->points.front() == this->points.back(); }
diff --git a/xs/t/09_polyline.t b/xs/t/09_polyline.t
index 0a7b8dcb0..5203ec5ef 100644
--- a/xs/t/09_polyline.t
+++ b/xs/t/09_polyline.t
@@ -89,40 +89,40 @@ is_deeply $polyline->pp, [ @$points, @$points ], 'append_polyline';
 }
 
 # disabled because we now use a more efficient but incomplete algorithm
-if (0) {
-    my $polyline = Slic3r::Polyline->new(
-        map [$_,10], (0,10,20,30,40,50,60)
-    );
-    {
-        my $expolygon = Slic3r::ExPolygon->new(Slic3r::Polygon->new(
-            [25,0], [55,0], [55,30], [25,30],
-        ));
-        my $p = $polyline->clone;
-        $p->simplify_by_visibility($expolygon);
-        is_deeply $p->pp, [
-            map [$_,10], (0,10,20,30,50,60)
-        ], 'simplify_by_visibility()';
-    }
-    {
-        my $expolygon = Slic3r::ExPolygon->new(Slic3r::Polygon->new(
-            [-15,0], [75,0], [75,30], [-15,30],
-        ));
-        my $p = $polyline->clone;
-        $p->simplify_by_visibility($expolygon);
-        is_deeply $p->pp, [
-            map [$_,10], (0,60)
-        ], 'simplify_by_visibility()';
-    }
-    {
-        my $expolygon = Slic3r::ExPolygon->new(Slic3r::Polygon->new(
-            [-15,0], [25,0], [25,30], [-15,30],
-        ));
-        my $p = $polyline->clone;
-        $p->simplify_by_visibility($expolygon);
-        is_deeply $p->pp, [
-            map [$_,10], (0,20,30,40,50,60)
-        ], 'simplify_by_visibility()';
-    }
-}
+#if (0) {
+#    my $polyline = Slic3r::Polyline->new(
+#        map [$_,10], (0,10,20,30,40,50,60)
+#    );
+#    {
+#        my $expolygon = Slic3r::ExPolygon->new(Slic3r::Polygon->new(
+#            [25,0], [55,0], [55,30], [25,30],
+#        ));
+#        my $p = $polyline->clone;
+#        $p->simplify_by_visibility($expolygon);
+#        is_deeply $p->pp, [
+#            map [$_,10], (0,10,20,30,50,60)
+#        ], 'simplify_by_visibility()';
+#    }
+#    {
+#        my $expolygon = Slic3r::ExPolygon->new(Slic3r::Polygon->new(
+#            [-15,0], [75,0], [75,30], [-15,30],
+#        ));
+#        my $p = $polyline->clone;
+#        $p->simplify_by_visibility($expolygon);
+#        is_deeply $p->pp, [
+#            map [$_,10], (0,60)
+#        ], 'simplify_by_visibility()';
+#    }
+#    {
+#        my $expolygon = Slic3r::ExPolygon->new(Slic3r::Polygon->new(
+#            [-15,0], [25,0], [25,30], [-15,30],
+#        ));
+#        my $p = $polyline->clone;
+#        $p->simplify_by_visibility($expolygon);
+#        is_deeply $p->pp, [
+#            map [$_,10], (0,20,30,40,50,60)
+#        ], 'simplify_by_visibility()';
+#    }
+#}
 
 __END__
diff --git a/xs/xsp/Polyline.xsp b/xs/xsp/Polyline.xsp
index 10bbb263f..7846ea5f4 100644
--- a/xs/xsp/Polyline.xsp
+++ b/xs/xsp/Polyline.xsp
@@ -31,8 +31,6 @@
     void extend_end(double distance);
     void extend_start(double distance);
     void simplify(double tolerance);
-    void simplify_by_visibility(ExPolygon* expolygon)
-        %code{% THIS->simplify_by_visibility(*expolygon); %};
     void split_at(Point* point, Polyline* p1, Polyline* p2)
         %code{% THIS->split_at(*point, p1, p2); %};
     bool is_straight();