diff --git a/srcpkgs/thunderbird/template b/srcpkgs/thunderbird/template
index a08417776bd..7b65916547a 100644
--- a/srcpkgs/thunderbird/template
+++ b/srcpkgs/thunderbird/template
@@ -1,4 +1,7 @@
 # Template build file for 'thunderbird'.
+#
+# THIS PKG MUST BE SYNCHRONIZED WITH "srcpkgs/thunderbird-i18n".
+#
 pkgname=thunderbird
 version=52.7.0
 revision=1