diff --git a/edocument.py b/edocument.py
index d3f5f6ef3f..cd7d68d693 100644
--- a/edocument.py
+++ b/edocument.py
@@ -12,6 +12,22 @@ from trytond.pool import Pool
 from trytond.rpc import RPC
 from trytond.transaction import Transaction
 
+# XXX fix: https://genshi.edgewall.org/ticket/582
+from genshi.template.astutil import ASTCodeGenerator, ASTTransformer
+if not hasattr(ASTCodeGenerator, 'visit_NameConstant'):
+    def visit_NameConstant(self, node):
+        if node.value is None:
+            self._write('None')
+        elif node.value is True:
+            self._write('True')
+        elif node.value is False:
+            self._write('False')
+        else:
+            raise Exception("Unknown NameConstant %r" % (node.value,))
+    ASTCodeGenerator.visit_NameConstant = visit_NameConstant
+if not hasattr(ASTTransformer, 'visit_NameConstant'):
+    # Re-use visit_Name because _clone is deleted
+    ASTTransformer.visit_NameConstant = ASTTransformer.visit_Name
 
 loader = genshi.template.TemplateLoader(
     os.path.join(os.path.dirname(__file__), 'template'),