diff --git a/3d-viewer/3d_draw_board_body.cpp b/3d-viewer/3d_draw_board_body.cpp
index d7419d098c..bde6004551 100644
--- a/3d-viewer/3d_draw_board_body.cpp
+++ b/3d-viewer/3d_draw_board_body.cpp
@@ -351,30 +351,13 @@ void EDA_3D_CANVAS::buildBoard3DView( GLuint aBoardList, GLuint aBodyOnlyList,
         if( bufferPolys.IsEmpty() )
             continue;
 
-        std::auto_ptr<SHAPE_FILE_IO> dumper( new SHAPE_FILE_IO( "poly_dump.txt", true ) );
-
         // Use Clipper lib to subtract holes to copper areas
 
-        dumper->BeginGroup( "clipper-zone" );
-
-        dumper->Write( &bufferPolys, "pre-simplify" );
         bufferPolys.Simplify();
-        dumper->Write( &bufferPolys, "post-simplify" );
-
         currLayerHoles.Simplify();
         allLayerHoles.Simplify();
 
-        //dumper->Write(&bufferPolys, "pre-sub");
-        //dumper->Write(&allLayerHoles, "holes");
-
-        // Add through holes (created only once) in current polygon holes list
-        //bufferPolys.BooleanSubtract( currLayerHoles );
-        //bufferPolys.Simplify();
         bufferPolys.BooleanSubtract( allLayerHoles );
-
-        //dumper->Write(&bufferPolys, "post-sub");
-        dumper->EndGroup();
-
         bufferPolys.Fracture();
 
         int thickness = GetPrm3DVisu().GetLayerObjectThicknessBIU( layer );
diff --git a/common/geometry/shape_poly_set.cpp b/common/geometry/shape_poly_set.cpp
index e3d6e2cb93..b70f84e1f8 100644
--- a/common/geometry/shape_poly_set.cpp
+++ b/common/geometry/shape_poly_set.cpp
@@ -257,7 +257,7 @@ void SHAPE_POLY_SET::Inflate( int aFactor, int aCircleSegmentsCount )
 
     PolyTree solution;
 
-    c.ArcTolerance = (double)aFactor / M_PI / aCircleSegmentsCount;
+    c.ArcTolerance = (double)fabs( aFactor ) / M_PI / aCircleSegmentsCount;
 
     c.Execute( solution, aFactor );
 
diff --git a/include/geometry/shape_poly_set.h b/include/geometry/shape_poly_set.h
index 7e378eeb70..58f7e46beb 100644
--- a/include/geometry/shape_poly_set.h
+++ b/include/geometry/shape_poly_set.h
@@ -251,7 +251,7 @@ class SHAPE_POLY_SET : public SHAPE
         void BooleanSubtract( const SHAPE_POLY_SET& b );
 
         ///> Performs outline inflation/deflation, using round corners.
-        void Inflate ( int aFactor, int aCircleSegmentsCount = 32 );
+        void Inflate( int aFactor, int aCircleSegmentsCount );
 
         ///> Converts a set of polygons with holes to a singe outline with "slits"/"fractures" connecting the outer ring
         ///> to the inner holes
diff --git a/pcbnew/zone_filling_algorithm.cpp b/pcbnew/zone_filling_algorithm.cpp
index 1b715cf4af..e56e786eb9 100644
--- a/pcbnew/zone_filling_algorithm.cpp
+++ b/pcbnew/zone_filling_algorithm.cpp
@@ -111,7 +111,7 @@ bool ZONE_CONTAINER::BuildFilledSolidAreasPolygons( BOARD* aPcb, SHAPE_POLY_SET*
         {
             int margin = m_ZoneMinThickness / 2;
             m_FilledPolysList = ConvertPolyListToPolySet( m_smoothedPoly->m_CornersList );
-            m_FilledPolysList.Inflate( -margin );
+            m_FilledPolysList.Inflate( -margin, 16 );
             m_FilledPolysList.Fracture();
         }
 
diff --git a/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp b/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
index d23562cef0..274f66e3be 100644
--- a/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
+++ b/pcbnew/zones_convert_brd_items_to_polygons_with_Boost.cpp
@@ -426,7 +426,7 @@ void ZONE_CONTAINER::AddClearanceAreasPolygonsToPolysList_NG( BOARD* aPcb )
 
     SHAPE_POLY_SET solidAreas = ConvertPolyListToPolySet( m_smoothedPoly->m_CornersList );
 
-    solidAreas.Inflate( -outline_half_thickness );
+    solidAreas.Inflate( -outline_half_thickness, segsPerCircle );
     solidAreas.Simplify();
 
     SHAPE_POLY_SET holes;
diff --git a/pcbnew/zones_convert_to_polygons_aux_functions.cpp b/pcbnew/zones_convert_to_polygons_aux_functions.cpp
index 8ac4e585c4..e9af2b1a6c 100644
--- a/pcbnew/zones_convert_to_polygons_aux_functions.cpp
+++ b/pcbnew/zones_convert_to_polygons_aux_functions.cpp
@@ -65,7 +65,7 @@ void ZONE_CONTAINER::TransformOutlinesShapeWithClearanceToPolygon(
     // Calculate the polygon with clearance
     // holes are linked to the main outline, so only one polygon is created.
     if( clearance )
-        aCornerBuffer.Inflate( clearance );
+        aCornerBuffer.Inflate( clearance, 16 );
 
     aCornerBuffer.Fracture( );
 }