diff --git a/build.xml b/build.xml
index 51f2b5bd5..bc84009ed 100644
--- a/build.xml
+++ b/build.xml
@@ -185,6 +185,7 @@ under the License.
     </path>
 
     <path id="ooxml.classpath">
+        <pathelement location="${ooxml.jsr173.jar}"/>
         <pathelement location="${ooxml.dom4j.jar}"/>
         <pathelement location="${ooxml.xmlbeans.jar}"/>
         <pathelement location="${ooxml.schemas.jar}"/>