diff --git a/src/main/scala/org/phenoscape/scowl/converters/SWRLArgs.scala b/src/main/scala/org/phenoscape/scowl/converters/SWRLArgs.scala
index e7fcfa9..a86d3cf 100644
--- a/src/main/scala/org/phenoscape/scowl/converters/SWRLArgs.scala
+++ b/src/main/scala/org/phenoscape/scowl/converters/SWRLArgs.scala
@@ -18,7 +18,7 @@ trait SWRLArgs {
 
     val iriPrefix = "urn:swrl#"
 
-    def toArgument(arg: Symbol): SWRLVariable = factory.getSWRLVariable(IRI.create(s"$iriPrefix${arg.toString}"))
+    def toArgument(arg: Symbol): SWRLVariable = factory.getSWRLVariable(IRI.create(s"$iriPrefix${arg.name}"))
 
   }