diff --git a/docs/tutorial/tutorial.lhs b/docs/tutorial/tutorial.lhs
index fcbc3eb..a10f861 100644
--- a/docs/tutorial/tutorial.lhs
+++ b/docs/tutorial/tutorial.lhs
@@ -12,7 +12,6 @@ We have written a small tutorial to help you (and ourselves) understand the grap
 Since this file is a literate haskell file, we start by importing some dependencies.
 
 > {-# LANGUAGE OverloadedStrings #-}
-> {-# LANGUAGE LambdaCase #-}
 > module Main where
 >
 > import Control.Monad.IO.Class (liftIO)
diff --git a/package.yaml b/package.yaml
index aaf496c..a45c040 100644
--- a/package.yaml
+++ b/package.yaml
@@ -30,6 +30,7 @@ dependencies:
 - base >= 4.7 && < 5
 - containers
 - megaparsec
+- parser-combinators
 - text
 - transformers
 - unordered-containers
diff --git a/src/Language/GraphQL/AST/Parser.hs b/src/Language/GraphQL/AST/Parser.hs
index 113b0a4..8268687 100644
--- a/src/Language/GraphQL/AST/Parser.hs
+++ b/src/Language/GraphQL/AST/Parser.hs
@@ -7,7 +7,7 @@ module Language.GraphQL.AST.Parser
     ) where
 
 import Control.Applicative (Alternative(..), optional)
-import Data.List.NonEmpty (NonEmpty(..))
+import qualified Control.Applicative.Combinators.NonEmpty as NonEmpty
 import Language.GraphQL.AST
 import qualified Language.GraphQL.AST.Document as Document
 import Language.GraphQL.AST.Lexer
@@ -17,7 +17,7 @@ import Text.Megaparsec (lookAhead, option, try, (<?>))
 document :: Parser Document.Document
 document = unicodeBOM
     >> spaceConsumer
-    >> lexeme (manyNE $ Document.ExecutableDefinition <$> definition)
+    >> lexeme (NonEmpty.some $ Document.ExecutableDefinition <$> definition)
 
 definition :: Parser ExecutableDefinition
 definition = DefinitionOperation <$> operationDefinition
@@ -44,7 +44,7 @@ operationType = Query <$ symbol "query"
 -- * SelectionSet
 
 selectionSet :: Parser SelectionSet
-selectionSet = braces $ manyNE selection
+selectionSet = braces $ NonEmpty.some selection
 
 selectionSetOpt :: Parser SelectionSetOpt
 selectionSetOpt = braces $ some selection
@@ -186,6 +186,3 @@ but :: Parser a -> Parser ()
 but pn = False <$ lookAhead pn <|> pure True >>= \case
     False -> empty
     True  -> pure ()
-
-manyNE :: Alternative f => f a -> f (NonEmpty a)
-manyNE p = (:|) <$> p <*> many p
diff --git a/stack.yaml b/stack.yaml
index 2155a49..a958e3c 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,4 +1,4 @@
-resolver: lts-14.19
+resolver: lts-14.20
 
 packages:
 - .