--- a/mail/confvars.sh
+++ b/mail/confvars.sh
@@ -38,17 +38,16 @@
 
 MOZ_APP_NAME=thunderbird
 MOZ_UPDATER=1
 MOZ_THUNDERBIRD=1
 MOZ_MATHML=
 MOZ_NO_ACTIVEX_SUPPORT=1
 MOZ_ACTIVEX_SCRIPTING_SUPPORT=
 MOZ_OJI=
-NECKO_DISK_CACHE=
 NECKO_PROTOCOLS_DEFAULT="data file ftp http res viewsource"
 MOZ_IMG_DECODERS_DEFAULT=`echo "$MOZ_IMG_DECODERS_DEFAULT" | sed "s/ xbm//"`
 MOZ_MAIL_NEWS=1
 if [ "$COMM_BUILD" ]; then
   MOZ_LDAP_XPCOM=1
 fi
 MOZ_STATIC_MAIL_BUILD=1
 MOZ_COMPOSER=1