diff --git a/semantic-ast/src/AST/Traversable1/Class.hs b/semantic-ast/src/AST/Traversable1/Class.hs
index 6a586daa9..15711b224 100644
--- a/semantic-ast/src/AST/Traversable1/Class.hs
+++ b/semantic-ast/src/AST/Traversable1/Class.hs
@@ -1,2 +1,3 @@
+-- | This module defines the 'Traversable1' class and its generic derivation using 'GTraversable1'. Note that any changes to this file will require recompilation of all of the AST modules, which is quite expensive; thus, most additions should be made in "AST.Traversable1" instead, and that that module should not be imported by the AST modules.
 module AST.Traversable1.Class
 () where