diff --git a/src/Language/Ruby/Syntax.hs b/src/Language/Ruby/Syntax.hs
index ba5cbb668..e02b4dacc 100644
--- a/src/Language/Ruby/Syntax.hs
+++ b/src/Language/Ruby/Syntax.hs
@@ -55,7 +55,8 @@ data Grammar = Program | Uninterpreted | BeginBlock | EndBlock | Undef | Alias |
 
 -- | Assignment from AST in Ruby’s grammar onto a program in Ruby’s syntax.
 assignment :: Assignment Grammar (Program Syntax (Maybe ()))
-assignment = foldr (>>) (return Nothing) <$> rule Program
+assignment = foldr (>>) (pure Nothing) <$> (rule Program <> children)
+
 comment :: Assignment Grammar (Program Syntax a)
 comment = wrapU . Comment.Comment <$> (rule Comment <> content)