diff --git a/idassigner.py b/idassigner.py
index 996eed4..77400c2 100644
--- a/idassigner.py
+++ b/idassigner.py
@@ -87,7 +87,7 @@ def main():
 
     xml_tree = etree.parse(args.teifile)
 
-    chapters = xml_tree.xpath("//t:div[@type='chapter']", namespaces=NS_MAP)
+    chapters = xml_tree.xpath("//t:div[@type='chapter' and not(@n='nonumber')]", namespaces=NS_MAP)
 
     logging.debug("Found %s chapters.", len(chapters))