--- a/mail/test/mozmill/session-store/test-session-store.js
+++ b/mail/test/mozmill/session-store/test-session-store.js
@@ -20,17 +20,17 @@ Cu.import("resource:///modules/sessionSt
 Cu.import("resource://gre/modules/Services.jsm");
 
 var folderA, folderB;
 
 // Default JSONFile save delay with saveSoon().
 var kSaveDelayMs = 1500;
 
 // With async file writes, use a delay larger than the session autosave timer.
-var asyncFileWriteDelayMS = 3000;
+var asyncFileWriteDelayMS = 6000;
 
 /* ........ Helper Functions ................*/
 
 /**
  * Reads the contents of the session file into a JSON object.
  */
 function readFile() {
   try {