diff --git a/lib/rdf/rdfxml/reader.rb b/lib/rdf/rdfxml/reader.rb
index 63e0da6..a1d3e0d 100644
--- a/lib/rdf/rdfxml/reader.rb
+++ b/lib/rdf/rdfxml/reader.rb
@@ -354,7 +354,7 @@ def nodeElement(el, ec)
           
           literal_opts = {}
           if datatype
-            literal_opts[:datatype] = datatype
+            literal_opts[:datatype] = RDF::URI.intern(datatype)
           else
             literal_opts[:language] = child_ec.language
           end