diff --git a/mozilla/calendar/install.rdf b/mozilla/calendar/install.rdf
index e0f2159ae3c..94b9a044f4e 100644
--- a/mozilla/calendar/install.rdf
+++ b/mozilla/calendar/install.rdf
@@ -24,7 +24,7 @@
         <!-- Thunderbird -->
         <em:id>{3550f703-e582-4d05-9a08-453d09bdfdc6}</em:id>
         <em:minVersion>0.7</em:minVersion>
-        <em:maxVersion>0.10+</em:maxVersion>
+        <em:maxVersion>1.0+</em:maxVersion>
       </Description>
     </em:targetApplication>