diff --git a/salak.cabal b/salak.cabal
--- a/salak.cabal
+++ b/salak.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: a30d96cdc96bcc24bbb445150b6b13acead0ad726df1fab2d6ffa6f6f065f826
+-- hash: f4e41d3d319929758bdec6b6e98dab0a80e8425760da0659ab8d1b56f45ecb58
 
 name:           salak
-version:        0.3.5.3
+version:        0.3.6
 synopsis:       Configuration (re)Loader and Parser.
 description:    This library defines a universal procedure to load configurations and parse properties, also supports reload configuration files.
 category:       Library, Configuration
@@ -48,12 +48,12 @@
     , filepath >=1.4.2 && <1.5
     , hashable >=1.2.7.0 && <1.4
     , heaps >=0.3.6 && <0.4
-    , megaparsec >=7.0.5 && <7.1
+    , megaparsec >=7.0.5 && <8.1
     , mtl >=2.2.2 && <2.3
     , scientific >=0.3.6 && <0.4
     , text >=1.2.3 && <1.3
     , time >=1.8.0 && <1.10
-    , unliftio-core >=0.1.2 && <0.2
+    , unliftio-core >=0.1.2 && <0.3
     , unordered-containers >=0.2.10 && <0.3
   default-language: Haskell2010
 
diff --git a/src/Salak/Internal.hs b/src/Salak/Internal.hs
--- a/src/Salak/Internal.hs
+++ b/src/Salak/Internal.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE CPP #-}
 -- |
 -- Module:      Salak.Internal
 -- Copyright:   2019 Daniel YU
@@ -52,7 +53,6 @@
 import           Control.Monad
 import           Control.Monad.Catch
 import           Control.Monad.Except
-import qualified Control.Monad.IO.Unlift as IU
 import           Control.Monad.Reader
 import qualified Control.Monad.State     as MS
 import           Data.Char               (toLower)
@@ -75,6 +75,9 @@
 #if __GLASGOW_HASKELL__ < 808
 import           Control.Monad.IO.Class  (MonadIO (..))
 #endif
+#if !MIN_VERSION_unliftio_core(0,2,0)
+import qualified Control.Monad.IO.Unlift as IU
+#endif
 
 data UpdateSource = UpdateSource
   {  ref    :: !(MVar Source)
@@ -110,11 +113,13 @@
     UpdateSource{..} <- MS.get
     liftIO $ readMVar lfunc >>= \lf -> lf callStack msg
 
+#if !MIN_VERSION_unliftio_core(0,2,0)
 instance (MonadThrow m, IU.MonadUnliftIO m) => IU.MonadUnliftIO (LoadSalakT m) where
   {-# INLINE askUnliftIO #-}
   askUnliftIO = do
     ut <- MS.get
     lift $ IU.withUnliftIO $ \u -> return (IU.UnliftIO (IU.unliftIO u . flip runLoad ut))
+#endif
 
 -- | Standard `MonadSalak` instance.
 newtype RunSalakT m a = RunSalakT { runSalakT :: ReaderT SourcePack m a }
@@ -127,11 +132,13 @@
   {-# INLINE askSourcePack #-}
   askSourcePack = ask
 
+#if !MIN_VERSION_unliftio_core(0,2,0)
 instance (MonadThrow m, IU.MonadUnliftIO m) => IU.MonadUnliftIO (RunSalakT m) where
   {-# INLINE askUnliftIO #-}
   askUnliftIO = do
     ut <- ask
     lift $ IU.withUnliftIO $ \u -> return (IU.UnliftIO (IU.unliftIO u . flip runReaderT ut . runSalakT))
+#endif
 
 -- | Basic loader
 loadTrie :: (MonadThrow m, MonadIO m) => Bool -> String -> (Int -> IO TraceSource) -> LoadSalakT m ()