diff --git a/mail/app/macbuild/Contents/Info.plist b/mail/app/macbuild/Contents/Info.plist
index 348be422b7ba..ac364b5f1bd0 100644
--- a/mail/app/macbuild/Contents/Info.plist
+++ b/mail/app/macbuild/Contents/Info.plist
@@ -21,7 +21,7 @@
 	<key>CFBundleShortVersionString</key>
 	<string>0.5a</string>
 	<key>CFBundleSignature</key>
-	<string>MOZZ</string>
+	<string>MOZM</string>
 	<key>CFBundleVersion</key>
 	<string>0.5a</string>
 	<key>NSAppleScriptEnabled</key>