diff --git a/umls2rdf.py b/umls2rdf.py
index f15b165..a3b4b36 100755
--- a/umls2rdf.py
+++ b/umls2rdf.py
@@ -18,6 +18,7 @@
 @prefix rdfs:  <http://www.w3.org/2000/01/rdf-schema#> .
 @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
 @prefix umls: <http://purl.bioontology.org/ontology/> .
+@prefix UMLSSC: <http://purl.bioontology.org/ontology/STY/> .
 
 """
 
@@ -32,7 +33,7 @@
 """)
 
 STY_URL = "http://purl.bioontology.org/ontology/STY/"
-HAS_STY = "umls:hasSTY"
+HAS_STY = "UMLSSC:hasSTY"
 HAS_AUI = "umls:aui"
 HAS_CUI = "umls:cui"
 HAS_TUI = "umls:STY"