Index: /branches/release-39/lib/MT/CMS/Template.pm
===================================================================
--- /branches/release-39/lib/MT/CMS/Template.pm (revision 2444)
+++ /branches/release-39/lib/MT/CMS/Template.pm (revision 2458)
@@ -1328,5 +1328,7 @@
     $obj->include_with_ssi( $app->param('include_with_ssi') ? 1 : 0 );
     $obj->cache_path( $app->param('cache_path'));
-    my $cache_expire_type = $app->param('cache_expire_type') || '';
+    my $cache_expire_type = defined $app->param('cache_expire_type')
+      ? $app->param('cache_expire_type')
+      : '0';
     $obj->cache_expire_type($cache_expire_type);
     my $period   = $app->param('cache_expire_period');