diff --git a/mozilla/mailnews/base/src/nsMsgRDFDataSource.cpp b/mozilla/mailnews/base/src/nsMsgRDFDataSource.cpp
index f906113733c..8f585b9e349 100644
--- a/mozilla/mailnews/base/src/nsMsgRDFDataSource.cpp
+++ b/mozilla/mailnews/base/src/nsMsgRDFDataSource.cpp
@@ -58,6 +58,10 @@ nsMsgRDFDataSource::Init()
     return rv;
 }
 
+void
+nsMsgRDFDataSource::Close()
+{
+}
 
 NS_IMPL_ADDREF(nsMsgRDFDataSource)
 NS_IMPL_RELEASE(nsMsgRDFDataSource)