diff --git a/ontology/sio.owl b/ontology/sio.owl
index 369c665f..c12d774a 100644
--- a/ontology/sio.owl
+++ b/ontology/sio.owl
@@ -19,7 +19,7 @@
         <vann:preferredNamespacePrefix xml:lang="en">sio</vann:preferredNamespacePrefix>
         <terms:license rdf:resource="http://creativecommons.org/licenses/by/4.0/"/>
         <cito:citesAsAuthority rdf:datatype="http://www.w3.org/2001/XMLSchema#anyURI">http://www.jbiomedsem.com/content/5/1/14</cito:citesAsAuthority>
-        <owl:versionInfo rdf:datatype="http://www.w3.org/2001/XMLSchema#string">1.27.0</owl:versionInfo>
+        <owl:versionInfo rdf:datatype="http://www.w3.org/2001/XMLSchema#string">1.28.0</owl:versionInfo>
         <terms:description xml:lang="en">The semanticscience integrated ontology (SIO) provides a simple, integrated ontology (types, relations) for objects, processes and their attributes.
 
 This project provides foundational support for the Bio2RDF (http://bio2rdf.org) and SADI (http://sadiframework.org) projects.