diff --git a/extensions/xforms/nsXFormsModelElement.cpp b/extensions/xforms/nsXFormsModelElement.cpp
index c01b53c789b4..7277b379b1d0 100644
--- a/extensions/xforms/nsXFormsModelElement.cpp
+++ b/extensions/xforms/nsXFormsModelElement.cpp
@@ -117,7 +117,8 @@ struct nsXFormsModelElement::ModelItemProperties
 
 nsXFormsModelElement::nsXFormsModelElement()
   : mElement(nsnull),
-    mSchemaCount(0)
+    mSchemaCount(0),
+    mPendingInstanceCount(0)
 {
 }