diff --git a/src/Data/Language/Ruby/AST.hs b/src/Data/Language/Ruby/AST.hs
index b5ba0d1..108ac48 100644
--- a/src/Data/Language/Ruby/AST.hs
+++ b/src/Data/Language/Ruby/AST.hs
@@ -27,12 +27,13 @@ module Data.Language.Ruby.AST
   ) where
 
 import Data.Aeson (parseJSON, Value(Null,Object,Number,Bool), withArray)
-import Prelude (Bounded)
+import Prelude (Bounded, drop)
 import Frelude hiding (String, Int)
 import qualified Frelude
 import qualified Data.Aeson.Types as Aeson
 import qualified Data.Vector as Vector
 import qualified Data.Scientific as Scientific
+import Data.Char (toLower)
 
 kebabCase :: Frelude.String -> Frelude.String
 kebabCase = Aeson.camelTo2 '-'
@@ -89,25 +90,7 @@ instance ToJSON Statement where
   toEncoding = Aeson.genericToEncoding opts
     where
     opts = aesonOptions { Aeson.constructorTagModifier = go }
-    go = \case
-      "StmtModule"   -> "module"
-      "StmtDef"      -> "def"
-      "StmtDefs"     -> "defs"
-      "StmtSend"     -> "send"
-      "StmtBlock"    -> "block"
-      "StmtConst"    -> "const"
-      "StmtCasgn"    -> "casgn"
-      "StmtArray"    -> "array"
-      "StmtSym"      -> "sym"
-      "StmtStr"      -> "str"
-      "StmtLvasgn"   -> "lvasgn"
-      "StmtLvar"     -> "lvar"
-      "StmtIvar"     -> "ivar"
-      "StmtSelf"     -> "self"
-      "StmtNil"      -> "nil"
-      "StmtInt"      -> "int"
-      "StmtCbase"    -> "cbase"
-      x              -> x
+    go s = toLower <$> drop 4 s
 
 instance FromJSON Statement where
   parseJSON v