diff --git a/bin/report/render/rml2pdf/trml2pdf.py b/bin/report/render/rml2pdf/trml2pdf.py
index 84e1882ebaf..63d8b4e38a3 100755
--- a/bin/report/render/rml2pdf/trml2pdf.py
+++ b/bin/report/render/rml2pdf/trml2pdf.py
@@ -424,8 +424,8 @@ class _rml_flowable(object):
 
 	def _table(self, node):
 		length = 0
-		colwidths = None
-		rowheights = None
+		colwidths = 0
+		rowheights = 0
 		data = []
 		childs = _child_get(node,'tr')
 		if not childs: