diff --git a/ontology/saref4ehaw.ttl b/ontology/saref4ehaw.ttl
index 4fa9f91a58cf3adc83a69ba3e909ec651168ee2a..df76803780012a317d55c2984df2008d970f356b 100644
--- a/ontology/saref4ehaw.ttl
+++ b/ontology/saref4ehaw.ttl
@@ -1,4 +1,3 @@
-@prefix : <http://www.semanticweb.org/owl/owlapi/turtle#> .
 @prefix owl: <http://www.w3.org/2002/07/owl#> .
 @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
 @prefix xml: <http://www.w3.org/XML/1998/namespace> .