diff --git a/extensions/inspector/install.rdf b/extensions/inspector/install.rdf
index ebcb11b4137..f5d22656026 100644
--- a/extensions/inspector/install.rdf
+++ b/extensions/inspector/install.rdf
@@ -21,7 +21,7 @@
       <!-- Thunderbird -->
       <Description>
         <em:id>{3550f703-e582-4d05-9a08-453d09bdfdc6}</em:id>
-        <em:minVersion>3.0a1</em:minVersion>
+        <em:minVersion>3.0a1pre</em:minVersion>
         <em:maxVersion>@THUNDERBIRD_VERSION@</em:maxVersion>
       </Description>
     </em:targetApplication>
@@ -30,7 +30,7 @@
       <!-- Sunbird -->
       <Description>
         <em:id>{718e30fb-e89b-41dd-9da7-e25a45638b28}</em:id>
-        <em:minVersion>0.6a1</em:minVersion>
+        <em:minVersion>0.6a1pre</em:minVersion>
         <em:maxVersion>@SUNBIRD_VERSION@</em:maxVersion>
       </Description>
     </em:targetApplication>