diff --git a/pygal/test/test_xml_filters.py b/pygal/test/test_xml_filters.py
new file mode 100644
index 0000000..fe1207a
--- /dev/null
+++ b/pygal/test/test_xml_filters.py
@@ -0,0 +1,52 @@
+# -*- coding: utf-8 -*-
+# This file is part of pygal
+#
+# A python svg graph plotting library
+# Copyright © 2012-2014 Kozea
+#
+# This library is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option) any
+# later version.
+#
+# This library is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with pygal. If not, see <http://www.gnu.org/licenses/>.
+from pygal import Bar
+
+class ChangeBarsXMLFilter(object):
+    def __init__(self, a, b):
+        self.data = [b[i] - a[i] for i in range(len(a))]
+
+    def __call__(self, T):
+        subplot = Bar(legend_at_bottom=True, explicit_size=True, width=800, height=150)
+        subplot.add("Difference", self.data)
+        subplot = subplot.render_tree()
+        subplot = subplot.xpath("g")[0]
+        T.insert(2, subplot)
+        T.xpath("g")[1].set('transform', 'translate(0,150), scale(1,0.75)')
+        return T
+
+def test_xml_filters_round_trip():
+    plot = Bar()
+    plot.add("A", [60, 75, 80, 78, 83, 90])
+    plot.add("B", [92, 87, 81, 73, 68, 55])
+    before = plot.render()
+    plot.add_xml_filter(lambda T: T)
+    after = plot.render()
+    assert before == after
+
+def test_xml_filters_change_bars():
+    plot = Bar(legend_at_bottom=True, explicit_size=True, width=800, height=600)
+    A = [60, 75, 80, 78, 83, 90]
+    B = [92, 87, 81, 73, 68, 55]
+    plot.add("A", A)
+    plot.add("B", B)
+    plot.add_xml_filter(ChangeBarsXMLFilter(A,B))
+    q = plot.render_tree()
+    assert len(q.xpath("g")) == 2
+    assert q.xpath("g")[1].attrib["transform"] == "translate(0,150), scale(1,0.75)"