diff --git a/etc/portage/package.use/thunderbird b/etc/portage/package.use/thunderbird
new file mode 100644
index 0000000..4bcc24e
--- /dev/null
+++ b/etc/portage/package.use/thunderbird
@@ -0,0 +1,9 @@
+# vim: set ft=gentoo-package-use :
+
+# Dustin C. Hatch <dustin@hatch.name> (15 May 2017)
+# Enable Thunderbird calendar extension
+mail-client/thunderbird lightning
+
+# Dustin C. Hatch <dustin@hatch.name> 28 Jul 2014
+# Enable LDAP address book support in Thunderbird
+mail-client/thunderbird ldap