diff --git a/lib/Slic3r/Layer/Region.pm b/lib/Slic3r/Layer/Region.pm
index 1d7550c44..fb6ba3450 100644
--- a/lib/Slic3r/Layer/Region.pm
+++ b/lib/Slic3r/Layer/Region.pm
@@ -36,7 +36,7 @@ has 'thin_walls' => (is => 'rw', default => sub { [] });
 has 'thin_fills' => (is => 'rw', default => sub { [] });
 
 # collection of surfaces for infill generation
-has 'fill_surfaces' => (is => 'rw', default => sub { [] });
+has 'fill_surfaces' => (is => 'rw', default => sub { Slic3r::Surface::Collection->new });
 
 # ordered collection of extrusion paths/loops to build all perimeters
 has 'perimeters' => (is => 'rw', default => sub { [] });
@@ -158,7 +158,7 @@ sub make_perimeters {
     my $gap_area_threshold  = $self->perimeter_flow->scaled_width ** 2;
     
     $self->perimeters([]);
-    $self->fill_surfaces([]);
+    $self->fill_surfaces->clear;
     $self->thin_fills([]);
     
     my @contours    = ();    # array of Polygons with ccw orientation
@@ -208,12 +208,14 @@ sub make_perimeters {
         # we offset by half the perimeter spacing (to get to the actual infill boundary)
         # and then we offset back and forth by the infill spacing to only consider the
         # non-collapsing regions
-        push @{ $self->fill_surfaces },
-            offset2_ex(
+        # use a bogus surface_type
+        $self->fill_surfaces->append(
+            map Slic3r::Surface->new(expolygon => $_, surface_type => S_TYPE_TOP), offset2_ex(
                 [ map $_->simplify(&Slic3r::SCALED_RESOLUTION), @last ],
                 -($perimeter_spacing/2 + $infill_spacing),
                 +$infill_spacing,
-            );
+            )
+        );
     }
     
     $self->_fill_gaps(\@gaps);
@@ -452,7 +454,8 @@ sub process_external_surfaces {
                 [ map $_->p, @new_surfaces ],
             )};
         }
-        @{$self->fill_surfaces} = @new_surfaces;
+        $self->fill_surfaces->clear;
+        $self->fill_surfaces->append(@new_surfaces);
     }
     
     # detect bridge direction (skip bottom layer)
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 531197582..e443f595b 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -428,7 +428,7 @@ sub export_gcode {
     }
     
     # free memory (note that support material needs fill_surfaces)
-    $_->fill_surfaces(undef) for map @{$_->regions}, map @{$_->layers}, @{$self->objects};
+    $_->fill_surfaces->clear for map @{$_->regions}, map @{$_->layers}, @{$self->objects};
     
     # make skirt
     $status_cb->(88, "Generating skirt");
diff --git a/lib/Slic3r/Print/Object.pm b/lib/Slic3r/Print/Object.pm
index d40350bc4..c2b3cafd4 100644
--- a/lib/Slic3r/Print/Object.pm
+++ b/lib/Slic3r/Print/Object.pm
@@ -427,16 +427,16 @@ sub detect_surfaces_type {
         # clip surfaces to the fill boundaries
         foreach my $layer (@{$self->layers}) {
             my $layerm = $layer->regions->[$region_id];
-            my $fill_boundaries = [ map @$_, @{$layerm->fill_surfaces} ];
-            @{$layerm->fill_surfaces} = ();
+            my $fill_boundaries = [ map $_->p, @{$layerm->fill_surfaces} ];
+            $layerm->fill_surfaces->clear;
             foreach my $surface (@{$layerm->slices}) {
                 my $intersection = intersection_ex(
                     [ $surface->p ],
                     $fill_boundaries,
                 );
-                push @{$layerm->fill_surfaces}, map Slic3r::Surface->new
+                $layerm->fill_surfaces->append(map Slic3r::Surface->new
                     (expolygon => $_, surface_type => $surface->surface_type),
-                    @$intersection;
+                    @$intersection);
             }
         }
     }
@@ -465,10 +465,12 @@ sub clip_fill_surfaces {
                     [ map @$_, @overhangs ],
                     [ map @{$_->expolygon}, grep $_->surface_type == S_TYPE_INTERNAL, @{$layerm->fill_surfaces} ],
                 )};
-            @{$layerm->fill_surfaces} = (
+            my @new_surfaces = (
                 @new_internal,
                 (grep $_->surface_type != S_TYPE_INTERNAL, @{$layerm->fill_surfaces}),
             );
+            $layerm->fill_surfaces->clear;
+            $layerm->fill_surfaces->append(@new_surfaces);
         }
         
         # get this layer's overhangs
@@ -523,7 +525,8 @@ sub bridge_over_infill {
                         [ map @$_, @$to_bridge ],
                         1,
                     )};
-                @{$layerm->fill_surfaces} = @new_surfaces;
+                $layerm->fill_surfaces->clear;
+                $layerm->fill_surfaces->append(@new_surfaces);
             }
             
             # exclude infill from the layers below if needed
@@ -550,7 +553,8 @@ sub bridge_over_infill {
                                 [ map @$_, @$to_bridge ],
                             )};
                         }
-                        @{$lower_layerm->fill_surfaces} = @new_surfaces;
+                        $lower_layerm->fill_surfaces->clear;
+                        $lower_layerm->fill_surfaces->append(@new_surfaces);
                     }
                     
                     $excess -= $self->layers->[$i]->height;
@@ -779,7 +783,8 @@ sub combine_infill {
                             )};
                     }
                     
-                    @{$layerm->fill_surfaces} = (@new_this_type, @other_types);
+                    $layerm->fill_surfaces->clear;
+                    $layerm->fill_surfaces->append(@new_this_type, @other_types);
                 }
             }
         }
diff --git a/xs/lib/Slic3r/XS.pm b/xs/lib/Slic3r/XS.pm
index 05ef2355f..30318ce25 100644
--- a/xs/lib/Slic3r/XS.pm
+++ b/xs/lib/Slic3r/XS.pm
@@ -60,4 +60,8 @@ sub clone {
     );
 }
 
+package Slic3r::Surface::Collection;
+use overload
+    '@{}' => sub { $_[0]->arrayref };
+
 1;
diff --git a/xs/src/SurfaceCollection.hpp b/xs/src/SurfaceCollection.hpp
new file mode 100644
index 000000000..e9f458dfd
--- /dev/null
+++ b/xs/src/SurfaceCollection.hpp
@@ -0,0 +1,26 @@
+#ifndef slic3r_SurfaceCollection_hpp_
+#define slic3r_SurfaceCollection_hpp_
+
+extern "C" {
+#include "EXTERN.h"
+#include "perl.h"
+#include "XSUB.h"
+#include "ppport.h"
+}
+
+#include "Surface.hpp"
+
+namespace Slic3r {
+
+typedef std::vector<Surface> Surfaces;
+
+class SurfaceCollection
+{
+    public:
+    Surfaces surfaces;
+    SV* arrayref();
+};
+
+}
+
+#endif
diff --git a/xs/t/05_surface.t b/xs/t/05_surface.t
index 16232191e..a881c8198 100644
--- a/xs/t/05_surface.t
+++ b/xs/t/05_surface.t
@@ -4,7 +4,7 @@ use strict;
 use warnings;
 
 use Slic3r::XS;
-use Test::More tests => 6;
+use Test::More tests => 10;
 
 my $square = [  # ccw
     [100, 100],
@@ -40,4 +40,15 @@ is $surface->bridge_angle, 30, 'bridge_angle';
 $surface->extra_perimeters(2);
 is $surface->extra_perimeters, 2, 'extra_perimeters';
 
+{
+    my $collection = Slic3r::Surface::Collection->new($surface, $surface->clone);
+    is scalar(@$collection), 2, 'collection has the right number of items';
+    is_deeply $collection->[0]->expolygon->arrayref, [$square, $hole_in_square],
+        'collection returns a correct surface expolygon';
+    $collection->clear;
+    is scalar(@$collection), 0, 'clear collection';
+    $collection->append($surface);
+    is scalar(@$collection), 1, 'append to collection';
+}
+
 __END__
diff --git a/xs/xsp/SurfaceCollection.xsp b/xs/xsp/SurfaceCollection.xsp
new file mode 100644
index 000000000..ef18fff48
--- /dev/null
+++ b/xs/xsp/SurfaceCollection.xsp
@@ -0,0 +1,49 @@
+%module{Slic3r::XS};
+
+%{
+#include <myinit.h>
+#include "SurfaceCollection.hpp"
+%}
+
+%name{Slic3r::Surface::Collection} class SurfaceCollection {
+    ~SurfaceCollection();
+    void clear()
+        %code{% THIS->surfaces.clear(); %};
+%{
+
+SurfaceCollection*
+SurfaceCollection::new(...)
+    CODE:
+        RETVAL = new SurfaceCollection ();
+        // ST(0) is class name, others are surfaces
+        RETVAL->surfaces.resize(items-1);
+        for (unsigned int i = 1; i < items; i++) {
+            RETVAL->surfaces[i-1] = *(Surface *)SvIV((SV*)SvRV( ST(i) ));
+        }
+    OUTPUT:
+        RETVAL
+
+SV*
+SurfaceCollection::arrayref()
+    CODE:
+        AV* av = newAV();
+        av_fill(av, THIS->surfaces.size()-1);
+        int i = 0;
+        for (Surfaces::iterator it = THIS->surfaces.begin(); it != THIS->surfaces.end(); ++it) {
+            SV* sv = newSV(0);
+            sv_setref_pv( sv, "Slic3r::Surface", new Surface(*it) );
+            av_store(av, i++, sv);
+        }
+        RETVAL = newRV_noinc((SV*)av);
+    OUTPUT:
+        RETVAL
+
+void
+SurfaceCollection::append(...)
+    CODE:
+        for (unsigned int i = 1; i < items; i++) {
+            THIS->surfaces.push_back(*(Surface *)SvIV((SV*)SvRV( ST(i) )));
+        }
+
+%}
+};
diff --git a/xs/xsp/my.map b/xs/xsp/my.map
index cbdb592ae..c5476e220 100644
--- a/xs/xsp/my.map
+++ b/xs/xsp/my.map
@@ -5,3 +5,4 @@ ExPolygon*      O_OBJECT
 ExPolygonCollection*    O_OBJECT
 SurfaceType     T_UV
 Surface*        O_OBJECT
+SurfaceCollection*      O_OBJECT