diff --git a/src/main/resources/alfresco/mimetype/mimetype-map.xml b/src/main/resources/alfresco/mimetype/mimetype-map.xml
index b2a7a663f5..29b4a52fad 100644
--- a/src/main/resources/alfresco/mimetype/mimetype-map.xml
+++ b/src/main/resources/alfresco/mimetype/mimetype-map.xml
@@ -22,6 +22,7 @@
 
          <mimetype mimetype="application/vnd.ms-project" display="Microsoft Project">
             <extension default="true">mpp</extension>
+            <extension>mpt</extension>
          </mimetype>
 
          <mimetype mimetype="image/vnd.adobe.photoshop" display="Adobe Photoshop">