diff --git a/src/rdf-mappings/functions.py b/src/rdf-mappings/functions.py
index 1ab5d981824e4fa2e1cb9fe1eca792762f2829eb..05402e8c7ed8e7ba3869c0440556e61d2eb6d30f 100644
--- a/src/rdf-mappings/functions.py
+++ b/src/rdf-mappings/functions.py
@@ -22,7 +22,7 @@ def construct_new_coa_uri(coa_id):
     if '_' in str(coa_id):
         last_id_part = coa_id.split('_', maxsplit=1)[1]
         first_id_part = str(coa_id.split('_', maxsplit=1)[0]).zfill(10)
-        complete_id = first_id_part + '_' + last_id_part
+        complete_id = first_id_part + '-' + last_id_part
     else:
         complete_id = str(coa_id).zfill(10)