--- a/calendar/lightning/install.rdf
+++ b/calendar/lightning/install.rdf
@@ -11,17 +11,17 @@
   <Description about="urn:mozilla:install-manifest">
     <!-- Target Application this extension can install into,
         with minimum and maximum supported versions. -->
     <em:targetApplication>
       <Description>
         <!-- thunderbird -->
         <em:id>{3550f703-e582-4d05-9a08-453d09bdfdc6}</em:id>
         <em:minVersion>@THUNDERBIRD_VERSION@</em:minVersion>
-        <em:maxVersion>@THUNDERBIRD_MAXVERSION@</em:maxVersion>
+        <em:maxVersion>@THUNDERBIRD_VERSION@</em:maxVersion>
       </Description>
     </em:targetApplication>
 
     <em:targetApplication>
       <Description>
         <!-- seamonkey -->
         <em:id>{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}</em:id>
         <em:minVersion>@SEAMONKEY_VERSION@</em:minVersion>