diff --git a/knora/knora.py b/knora/knora.py
index f27af1207..4d56012d7 100755
--- a/knora/knora.py
+++ b/knora/knora.py
@@ -1480,7 +1480,7 @@ def process_properties(propinfo: Dict, valuestr: any):
             return xmlopt, value
 
         if self.schema["resources"].get(resclass) is None:
-            raise KnoraError('Resource class is not defined in ontlogy!')
+            raise KnoraError('Resource class is not defined in ontology!')
         resnode = self.new_xml_element(self.proj_prefix + ':' + resclass, {'id': str(id)})
 
         labelnode = self.new_xml_element('knoraXmlImport:label')