diff --git a/lib/Slic3r/Geometry.pm b/lib/Slic3r/Geometry.pm
index 86e7bf96e4..b5bec3a8d7 100644
--- a/lib/Slic3r/Geometry.pm
+++ b/lib/Slic3r/Geometry.pm
@@ -20,7 +20,7 @@ our @EXPORT_OK = qw(
     shortest_path collinear scale unscale merge_collinear_lines
     rad2deg_dir bounding_box_center line_intersects_any douglas_peucker
     polyline_remove_short_segments normal triangle_normal polygon_is_convex
-    scaled_epsilon bounding_box_3D
+    scaled_epsilon bounding_box_3D size_3D
 );
 
 
@@ -721,6 +721,13 @@ sub bounding_box_3D {
     return @extents;
 }
 
+sub size_3D {
+    my ($points) = @_;
+    
+    my @extents = bounding_box_3D($points);
+    return map $extents[$_][MAX] - $extents[$_][MIN], (X,Y,Z);
+}
+
 sub angle3points {
     my ($p1, $p2, $p3) = @_;
     # p1 is the center
diff --git a/lib/Slic3r/TriangleMesh.pm b/lib/Slic3r/TriangleMesh.pm
index 90ff45614e..9818196dbf 100644
--- a/lib/Slic3r/TriangleMesh.pm
+++ b/lib/Slic3r/TriangleMesh.pm
@@ -386,9 +386,7 @@ sub extents {
 
 sub size {
     my $self = shift;
-    
-    my @extents = $self->extents;
-    return map $extents[$_][MAX] - $extents[$_][MIN], (X,Y,Z);
+    return Slic3r::Geometry::size_3D($self->vertices);
 }
 
 sub slice_facet {