diff --git a/extensible-effects.cabal b/extensible-effects.cabal
--- a/extensible-effects.cabal
+++ b/extensible-effects.cabal
@@ -6,7 +6,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             2.0.0.0
+version:             2.0.0.2
 
 -- A short (one-line) description of the package.
 synopsis:            An Alternative to Monad Transformers
diff --git a/src/Control/Eff.hs b/src/Control/Eff.hs
--- a/src/Control/Eff.hs
+++ b/src/Control/Eff.hs
@@ -107,6 +107,7 @@
   fmap f (E u q) = E u (q |> (Val . f)) -- does no mapping yet!
 
 instance Applicative (Eff r) where
+  {-# INLINE pure #-}
   pure = Val
   Val f <*> Val x = Val $ f x
   Val f <*> E u q = E u (q |> (Val . f))
@@ -116,7 +117,7 @@
 instance Monad (Eff r) where
   {-# INLINE return #-}
   {-# INLINE [2] (>>=) #-}
-  return x = Val x
+  return = pure
   Val x >>= k = k x
   E u q >>= k = E u (q |> k)          -- just accumulates continuations
 {-
diff --git a/src/Control/Eff/Choose.hs b/src/Control/Eff/Choose.hs
--- a/src/Control/Eff/Choose.hs
+++ b/src/Control/Eff/Choose.hs
@@ -1,10 +1,9 @@
---{-# OPTIONS_GHC -Werror #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeOperators #-}
-
+{-# LANGUAGE Safe #-}
 -- The following is needed to define MonadPlus instance. It is decidable
 -- (there is no recursion!), but GHC cannot see that.
 {-# LANGUAGE UndecidableInstances #-}
diff --git a/src/Control/Eff/Coroutine.hs b/src/Control/Eff/Coroutine.hs
--- a/src/Control/Eff/Coroutine.hs
+++ b/src/Control/Eff/Coroutine.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE TypeOperators #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE DataKinds #-}
diff --git a/src/Control/Eff/Example.hs b/src/Control/Eff/Example.hs
--- a/src/Control/Eff/Example.hs
+++ b/src/Control/Eff/Example.hs
@@ -1,6 +1,7 @@
 {-# OPTIONS_GHC -Werror #-}
 {-# LANGUAGE TypeOperators, GADTs, DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE Safe #-}
 
 -- | Example usage of "Control.Eff1"
 module Control.Eff.Example where
diff --git a/src/Control/Eff/Exception.hs b/src/Control/Eff/Exception.hs
--- a/src/Control/Eff/Exception.hs
+++ b/src/Control/Eff/Exception.hs
@@ -1,9 +1,9 @@
---{-# OPTIONS_GHC -Werror #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE Safe #-}
 -- | Exception-producing and exception-handling effects
 module Control.Eff.Exception ( Exc (..)
                             , Fail
diff --git a/src/Control/Eff/Fresh.hs b/src/Control/Eff/Fresh.hs
--- a/src/Control/Eff/Fresh.hs
+++ b/src/Control/Eff/Fresh.hs
@@ -1,7 +1,5 @@
---{-# OPTIONS_GHC -Werror #-}
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE DeriveFunctor #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GADTs #-}
diff --git a/src/Control/Eff/Lift.hs b/src/Control/Eff/Lift.hs
--- a/src/Control/Eff/Lift.hs
+++ b/src/Control/Eff/Lift.hs
@@ -1,11 +1,7 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ < 708
-{-# LANGUAGE Trustworthy #-}
-#else
 {-# LANGUAGE Safe #-}
-#endif
 -- | Lifting primitive Monad types to effectful computations.
 -- We only allow a single Lifted Monad because Monads aren't commutative
 -- (e.g. Maybe (IO a) is functionally distinct from IO (Maybe a)).
diff --git a/src/Control/Eff/NdetEff.hs b/src/Control/Eff/NdetEff.hs
--- a/src/Control/Eff/NdetEff.hs
+++ b/src/Control/Eff/NdetEff.hs
@@ -5,6 +5,7 @@
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE Safe #-}
 -- The following is needed to define MonadPlus instance. It is decidable
 -- (there is no recursion!), but GHC cannot see that.
 {-# LANGUAGE UndecidableInstances #-}
diff --git a/src/Control/Eff/Operational.hs b/src/Control/Eff/Operational.hs
--- a/src/Control/Eff/Operational.hs
+++ b/src/Control/Eff/Operational.hs
@@ -6,12 +6,7 @@
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-#if __GLASGOW_HASKELL__ < 708
-{-# LANGUAGE Trustworthy #-}
-#else
 {-# LANGUAGE Safe #-}
-#endif
 
 -- | Operational Monad (<https://wiki.haskell.org/Operational>) implemented with
 -- extensible effects.
@@ -50,6 +45,7 @@
 -- @
 --main :: IO ()
 --main = do
---    putStrLn . fst . 'run' . 'runMonoidWriter' . 'evalState' [\"foo\",\"bar\"] $ 'runProgram' adventPure prog
+--    let comp = 'runProgram' adventPure prog
+--    putStrLn . fst . 'run' . 'runMonoidWriter' $ 'evalState' comp [\"foo\",\"bar\"]
 --    'runLift' $ 'runProgram' adventIO prog
 -- @
diff --git a/src/Control/Eff/Operational/Example.hs b/src/Control/Eff/Operational/Example.hs
--- a/src/Control/Eff/Operational/Example.hs
+++ b/src/Control/Eff/Operational/Example.hs
@@ -1,8 +1,7 @@
-{-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE CPP #-}
--- {-# LANGUAGE Safe #-}
+{-# LANGUAGE Safe #-}
 
 -- | Example usage of "Control.Eff.Operational".
 module Control.Eff.Operational.Example where
@@ -13,17 +12,11 @@
 import Control.Eff.Lift
 import Control.Eff.Writer.Lazy
 import Control.Eff.State.Lazy
-import Data.Typeable
 
-#if __GLASGOW_HASKELL__ >= 708
-#define Typeable1 Typeable
-#endif
-
 -- | Define data using GADTs.
 data Jail a where
    Print :: String -> Jail ()
    Scan :: Jail String
-    deriving (Typeable)
 
 prog :: Member (Program Jail) r => Eff r ()
 prog = do
@@ -33,7 +26,7 @@
    singleton $ Print ("the input is " ++ str)
 
 -- | Then, implements interpreters from the data to effects.
-adventIO :: (Member (Lift IO) r, SetMember Lift (Lift IO) r) => Jail a -> Eff r a
+adventIO :: (SetMember Lift (Lift IO) r) => Jail a -> Eff r a
 adventIO (Print a) = lift $ putStrLn a
 adventIO Scan = lift getLine
 
diff --git a/src/Control/Eff/Reader/Lazy.hs b/src/Control/Eff/Reader/Lazy.hs
--- a/src/Control/Eff/Reader/Lazy.hs
+++ b/src/Control/Eff/Reader/Lazy.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE Safe #-}
 -- | Lazy read-only state
 module Control.Eff.Reader.Lazy ( Reader (..)
                               , ask
diff --git a/src/Control/Eff/Reader/Strict.hs b/src/Control/Eff/Reader/Strict.hs
--- a/src/Control/Eff/Reader/Strict.hs
+++ b/src/Control/Eff/Reader/Strict.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE Safe #-}
 -- | Strict read-only state
 module Control.Eff.Reader.Strict ( Reader (..)
                               , ask
diff --git a/src/Control/Eff/State/Lazy.hs b/src/Control/Eff/State/Lazy.hs
--- a/src/Control/Eff/State/Lazy.hs
+++ b/src/Control/Eff/State/Lazy.hs
@@ -6,6 +6,7 @@
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE Trustworthy #-}
 -- | Lazy state effect
 module Control.Eff.State.Lazy where
 
diff --git a/src/Control/Eff/State/LazyState.hs b/src/Control/Eff/State/LazyState.hs
--- a/src/Control/Eff/State/LazyState.hs
+++ b/src/Control/Eff/State/LazyState.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE NoMonomorphismRestriction #-}
+{-# LANGUAGE Safe #-}
 
 -- | On-demand state computation:
 -- example taken from Edward Kmett's comment here:
diff --git a/src/Control/Eff/State/Strict.hs b/src/Control/Eff/State/Strict.hs
--- a/src/Control/Eff/State/Strict.hs
+++ b/src/Control/Eff/State/Strict.hs
@@ -7,6 +7,7 @@
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE Trustworthy #-}
 -- | Strict state effect
 module Control.Eff.State.Strict where
 
diff --git a/src/Control/Eff/Trace.hs b/src/Control/Eff/Trace.hs
--- a/src/Control/Eff/Trace.hs
+++ b/src/Control/Eff/Trace.hs
@@ -1,6 +1,5 @@
 {-# OPTIONS_GHC -Werror #-}
 {-# LANGUAGE TypeOperators #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GADTs, DataKinds #-}
diff --git a/src/Control/Eff/Writer/Lazy.hs b/src/Control/Eff/Writer/Lazy.hs
--- a/src/Control/Eff/Writer/Lazy.hs
+++ b/src/Control/Eff/Writer/Lazy.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE Safe #-}
 -- | Lazy write-only state
 module Control.Eff.Writer.Lazy ( Writer(..)
                                , tell
diff --git a/src/Control/Eff/Writer/Strict.hs b/src/Control/Eff/Writer/Strict.hs
--- a/src/Control/Eff/Writer/Strict.hs
+++ b/src/Control/Eff/Writer/Strict.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE NoMonomorphismRestriction #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE Safe #-}
 -- | Strict write-only state
 module Control.Eff.Writer.Strict ( Writer(..)
                                , tell