diff --git a/src/Language/Lambda/Expression.hs b/src/Language/Lambda/Expression.hs
index 1475cb09bf3c8d0f0f7e93f4f9f7ea7f1c46cb57..13e29b2ee6c9be55ed5fc4029d0e5dff2abfca3c 100644
--- a/src/Language/Lambda/Expression.hs
+++ b/src/Language/Lambda/Expression.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE FlexibleInstances #-}
 module Language.Lambda.Expression where
 
-import Prelude hiding (abs, uncurry)
+import Prelude hiding (uncurry)
 
 import Language.Lambda.Util.PrettyPrint
 
diff --git a/src/Language/Lambda/Parser.hs b/src/Language/Lambda/Parser.hs
index 821af3b095a673c91b446d8cf545173540ca2d1c..99fe676bc282ae2551ca2f305daca78f535a1340 100644
--- a/src/Language/Lambda/Parser.hs
+++ b/src/Language/Lambda/Parser.hs
@@ -1,7 +1,7 @@
 module Language.Lambda.Parser (parseExpr) where
 
 import Control.Monad
-import Prelude hiding (abs, curry, id)
+import Prelude hiding (abs, curry)
 
 import Text.Parsec
 import Text.Parsec.String
diff --git a/src/Language/SystemF/Parser.hs b/src/Language/SystemF/Parser.hs
index 23aae48e2eb3b3f534da407a133b8d9b8cc25195..30505da05c3658448adf090285810fe40ac6b37f 100644
--- a/src/Language/SystemF/Parser.hs
+++ b/src/Language/SystemF/Parser.hs
@@ -4,6 +4,7 @@ module Language.SystemF.Parser (
   ) where
 
 import Control.Monad
+import Data.Functor
 import Prelude hiding (abs)
 
 import Text.Parsec
@@ -53,7 +54,7 @@ ty :: Parser (Ty String)
 ty = try arrow
 
 arrow :: Parser (Ty String)
-arrow = chainr1 tyterm (symbol' "->" *> return TyArrow)
+arrow = chainr1 tyterm (symbol' "->" $> TyArrow)
 
 tyterm :: Parser (Ty String)
 tyterm = tyvar <|> parens ty
diff --git a/stack.yaml b/stack.yaml
index 3fc81bbf02214ee0fd835f5023a0c7fcb5f5399e..0639b744146dd16259280a22e4f7bdb5065a3fc5 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -5,4 +5,5 @@ packages:
 extra-deps:
 - Shellac-0.9.9
 - Shellac-readline-0.9.9
-resolver: lts-8.19
+- readline-1.0.3.0
+resolver: lts-10.0