diff --git a/mailnews/local/tests/mailbox/mailboxTest.cpp b/mailnews/local/tests/mailbox/mailboxTest.cpp
index 3e32e2269a30..79dfc9a3b2d2 100644
--- a/mailnews/local/tests/mailbox/mailboxTest.cpp
+++ b/mailnews/local/tests/mailbox/mailboxTest.cpp
@@ -298,7 +298,7 @@ nsresult nsMailboxTestDriver::RunDriver()
 	return status;
 }
 
-static const char kMsgRootFolderPref[] = "mailnews.rootFolder";
+static const char kMsgRootFolderPref[] = "mail.rootFolder";
 
 void nsMailboxTestDriver::InitializeTestDriver()
 {