diff --git a/ChangeLog b/ChangeLog
index d31ae0065..a254d5c1c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,6 +13,10 @@
 	* UI/MailerUI/UIxMailEditor.m (-validateForSend): don't force the
 	subject to be defined.
 
+	* SoObjects/Mailer/SOGoMailObject+Draft.m (-subjectForReply): make
+	sure subject is a defined value to avoid "null" strings in the
+	reply message.
+
 2012-05-28  Francis Lachapelle  <flachapelle@inverse.ca>
 
 	* UI/WebServerResources/SchedulerUI.js (validateUploadForm): hide
diff --git a/SoObjects/Mailer/SOGoMailObject+Draft.m b/SoObjects/Mailer/SOGoMailObject+Draft.m
index b0aec21ed..aede6309e 100644
--- a/SoObjects/Mailer/SOGoMailObject+Draft.m
+++ b/SoObjects/Mailer/SOGoMailObject+Draft.m
@@ -59,6 +59,8 @@
   hasPrefix = NO;
 
   subject = [self decodedSubject];
+  if (![subject length]) subject = @"";
+
   i = 0;
   while (!hasPrefix && replyPrefixes[i])
     if ([subject hasPrefix: replyPrefixes[i]])