diff --git a/nor2tei.py b/nor2tei.py
index 6bbb53b..93b9111 100644
--- a/nor2tei.py
+++ b/nor2tei.py
@@ -69,7 +69,7 @@
         fileDesc = ET.SubElement(teiHeader, "fileDesc")
         titleStmt = ET.SubElement(fileDesc, "titleStmt")
         textSigle = ET.SubElement(titleStmt, "textSigle")
-        textSigle.text = "NO/" + f"{j:03}" + "." + f"{i:05}"
+        textSigle.text = "NOR/" + f"{j:03}" + "." + f"{i:05}"
         sourceDesc = ET.SubElement(fileDesc, "sourceDesc")
         analytic = ET.SubElement(sourceDesc, "analytic")
         title = ET.SubElement(titleStmt, "title")