diff --git a/tl.tl b/tl.tl
index 421a6b702..263e43683 100644
--- a/tl.tl
+++ b/tl.tl
@@ -10004,6 +10004,8 @@ tl.type_check = function(ast: Node, opts: TypeCheckOptions): Result, string
                end
                node.type = BOOLEAN
             elseif node.op.op == ":" then
+               -- we handle ':' separately from '.' because ':' is specific to records,
+               -- so we produce different error messages
                if lax and (is_unknown(a) or a.typename == "typevar") then
                   if node.e1.kind == "variable" then
                      add_unknown_dot(node.e1, node.e1.tk .. "." .. node.e2.tk)