diff --git a/webapp/src/edu/cornell/mannlib/vitro/webapp/dao/jena/DataPropertyDaoJena.java b/webapp/src/edu/cornell/mannlib/vitro/webapp/dao/jena/DataPropertyDaoJena.java
index e8112b3e6..f0d6f4c3e 100644
--- a/webapp/src/edu/cornell/mannlib/vitro/webapp/dao/jena/DataPropertyDaoJena.java
+++ b/webapp/src/edu/cornell/mannlib/vitro/webapp/dao/jena/DataPropertyDaoJena.java
@@ -459,7 +459,13 @@ public class DataPropertyDaoJena extends PropertyDaoJena implements
     }
     
     public DataProperty getDataPropertyByURI(String dataPropertyURI) {
-        return datapropFromOntProperty(getOntModelSelector().getTBoxModel().getDatatypeProperty(dataPropertyURI));
+        OntModel tboxModel = getOntModelSelector().getTBoxModel();
+        tboxModel.enterCriticalSection(Lock.READ);
+        try {
+            return datapropFromOntProperty(tboxModel.getDatatypeProperty(dataPropertyURI));
+        } finally {
+            tboxModel.leaveCriticalSection();
+        }
     }
 
     public String insertDataProperty(DataProperty dtp) throws InsertException{