diff --git a/lib/languages.nix b/lib/languages.nix
index f07880b..18cfc37 100644
--- a/lib/languages.nix
+++ b/lib/languages.nix
@@ -1,4 +1,7 @@
+# From home-manager: https://github.com/nix-community/home-manager/blob/master/modules/lib/booleans.nix
 {lib}: {
+  # Converts a boolean to a yes/no string. This is used in lots of
+  # configuration formats.
   diagnosticsToLua = {
     lang,
     config,