diff --git a/lib/Slic3r/Polygon.pm b/lib/Slic3r/Polygon.pm
index 68f1002e..4cc51d61 100644
--- a/lib/Slic3r/Polygon.pm
+++ b/lib/Slic3r/Polygon.pm
@@ -141,7 +141,7 @@ sub split_at_index {
     my $self = shift;
     my ($index) = @_;
     
-    return (ref $self)->new(
+    return Slic3r::Polyline->new(
         @$self[$index .. $#$self], 
         @$self[0 .. $index],
     );
diff --git a/t/geometry.t b/t/geometry.t
index f5c2f412..c0e1f753 100644
--- a/t/geometry.t
+++ b/t/geometry.t
@@ -2,7 +2,7 @@ use Test::More;
 use strict;
 use warnings;
 
-plan tests => 21;
+plan tests => 23;
 
 BEGIN {
     use FindBin;
@@ -164,4 +164,13 @@ is Slic3r::Geometry::can_connect_points(@$points, $polygons), 0, 'can_connect_po
     ], 'polyline_lines';
 }
 
+#==========================================================
+
+{
+    my $polyline = Slic3r::Polygon->new([0, 0], [10, 0], [5, 5]);
+    my $result = $polyline->split_at_index(1);
+    is ref($result), 'Slic3r::Polyline', 'split_at_index returns polyline';
+    is_deeply $result, [ [10, 0], [5, 5], [0, 0], [10, 0] ], 'split_at_index';
+}
+
 #==========================================================
\ No newline at end of file