diff --git a/.stylish-haskell.yaml b/.stylish-haskell.yaml
new file mode 100644
index 0000000..580712b
--- /dev/null
+++ b/.stylish-haskell.yaml
@@ -0,0 +1,233 @@
+# stylish-haskell configuration file
+# ==================================
+
+# The stylish-haskell tool is mainly configured by specifying steps. These steps
+# are a list, so they have an order, and one specific step may appear more than
+# once (if needed). Each file is processed by these steps in the given order.
+steps:
+  # Convert some ASCII sequences to their Unicode equivalents. This is disabled
+  # by default.
+  # - unicode_syntax:
+  #     # In order to make this work, we also need to insert the UnicodeSyntax
+  #     # language pragma. If this flag is set to true, we insert it when it's
+  #     # not already present. You may want to disable it if you configure
+  #     # language extensions using some other method than pragmas. Default:
+  #     # true.
+  #     add_language_pragma: true
+
+  # Align the right hand side of some elements.  This is quite conservative
+  # and only applies to statements where each element occupies a single
+  # line.
+  - simple_align:
+      cases: true
+      top_level_patterns: true
+      records: true
+
+  # Import cleanup
+  - imports:
+      # There are different ways we can align names and lists.
+      #
+      # - global: Align the import names and import list throughout the entire
+      #   file.
+      #
+      # - file: Like global, but don't add padding when there are no qualified
+      #   imports in the file.
+      #
+      # - group: Only align the imports per group (a group is formed by adjacent
+      #   import lines).
+      #
+      # - none: Do not perform any alignment.
+      #
+      # Default: global.
+      align: global
+
+      # The following options affect only import list alignment.
+      #
+      # List align has following options:
+      #
+      # - after_alias: Import list is aligned with end of import including
+      #   'as' and 'hiding' keywords.
+      #
+      #   > import qualified Data.List      as List (concat, foldl, foldr, head,
+      #   >                                          init, last, length)
+      #
+      # - with_alias: Import list is aligned with start of alias or hiding.
+      #
+      #   > import qualified Data.List      as List (concat, foldl, foldr, head,
+      #   >                                 init, last, length)
+      #
+      # - new_line: Import list starts always on new line.
+      #
+      #   > import qualified Data.List      as List
+      #   >     (concat, foldl, foldr, head, init, last, length)
+      #
+      # Default: after_alias
+      list_align: after_alias
+
+      # Right-pad the module names to align imports in a group:
+      #
+      # - true: a little more readable
+      #
+      #   > import qualified Data.List       as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #   > import qualified Data.List.Extra as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #
+      # - false: diff-safe
+      #
+      #   > import qualified Data.List as List (concat, foldl, foldr, init,
+      #   >                                     last, length)
+      #   > import qualified Data.List.Extra as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #
+      # Default: true
+      pad_module_names: true
+
+      # Long list align style takes effect when import is too long. This is
+      # determined by 'columns' setting.
+      #
+      # - inline: This option will put as much specs on same line as possible.
+      #
+      # - new_line: Import list will start on new line.
+      #
+      # - new_line_multiline: Import list will start on new line when it's
+      #   short enough to fit to single line. Otherwise it'll be multiline.
+      #
+      # - multiline: One line per import list entry.
+      #   Type with constructor list acts like single import.
+      #
+      #   > import qualified Data.Map as M
+      #   >     ( empty
+      #   >     , singleton
+      #   >     , ...
+      #   >     , delete
+      #   >     )
+      #
+      # Default: inline
+      long_list_align: inline
+
+      # Align empty list (importing instances)
+      #
+      # Empty list align has following options
+      #
+      # - inherit: inherit list_align setting
+      #
+      # - right_after: () is right after the module name:
+      #
+      #   > import Vector.Instances ()
+      #
+      # Default: inherit
+      empty_list_align: inherit
+
+      # List padding determines indentation of import list on lines after import.
+      # This option affects 'long_list_align'.
+      #
+      # - <integer>: constant value
+      #
+      # - module_name: align under start of module name.
+      #   Useful for 'file' and 'group' align settings.
+      list_padding: 4
+
+      # Separate lists option affects formatting of import list for type
+      # or class. The only difference is single space between type and list
+      # of constructors, selectors and class functions.
+      #
+      # - true: There is single space between Foldable type and list of it's
+      #   functions.
+      #
+      #   > import Data.Foldable (Foldable (fold, foldl, foldMap))
+      #
+      # - false: There is no space between Foldable type and list of it's
+      #   functions.
+      #
+      #   > import Data.Foldable (Foldable(fold, foldl, foldMap))
+      #
+      # Default: true
+      separate_lists: true
+
+      # Space surround option affects formatting of import lists on a single
+      # line. The only difference is single space after the initial
+      # parenthesis and a single space before the terminal parenthesis.
+      #
+      # - true: There is single space associated with the enclosing
+      #   parenthesis.
+      #
+      #   > import Data.Foo ( foo )
+      #
+      # - false: There is no space associated with the enclosing parenthesis
+      #
+      #   > import Data.Foo (foo)
+      #
+      # Default: false
+      space_surround: false
+
+  # Language pragmas
+  - language_pragmas:
+      # We can generate different styles of language pragma lists.
+      #
+      # - vertical: Vertical-spaced language pragmas, one per line.
+      #
+      # - compact: A more compact style.
+      #
+      # - compact_line: Similar to compact, but wrap each line with
+      #   `{-#LANGUAGE #-}'.
+      #
+      # Default: vertical.
+      style: vertical
+
+      # Align affects alignment of closing pragma brackets.
+      #
+      # - true: Brackets are aligned in same column.
+      #
+      # - false: Brackets are not aligned together. There is only one space
+      #   between actual import and closing bracket.
+      #
+      # Default: true
+      align: true
+
+      # stylish-haskell can detect redundancy of some language pragmas. If this
+      # is set to true, it will remove those redundant pragmas. Default: true.
+      remove_redundant: true
+
+  # Replace tabs by spaces. This is disabled by default.
+  # - tabs:
+  #     # Number of spaces to use for each tab. Default: 8, as specified by the
+  #     # Haskell report.
+  #     spaces: 8
+
+  # Remove trailing whitespace
+  - trailing_whitespace: {}
+
+# A common setting is the number of columns (parts of) code will be wrapped
+# to. Different steps take this into account. Default: 80.
+columns: 80
+
+# By default, line endings are converted according to the OS. You can override
+# preferred format here.
+#
+# - native: Native newline format. CRLF on Windows, LF on other OSes.
+#
+# - lf: Convert to LF ("\n").
+#
+# - crlf: Convert to CRLF ("\r\n").
+#
+# Default: native.
+newline: native
+
+# Sometimes, language extensions are specified in a cabal file or from the
+# command line instead of using language pragmas in the file. stylish-haskell
+# needs to be aware of these, so it can parse the file correctly.
+#
+# No language extensions are enabled by default.
+language_extensions:
+  - BangPatterns
+  - FlexibleContexts
+  - FlexibleInstances
+  - MultiParamTypeClasses
+  - MultiWayIf
+  - NoImplicitPrelude
+  - OverloadedStrings
+  - RankNTypes
+  - ScopedTypeVariables
+  - TupleSections
+  - TypeFamilies
diff --git a/minio-hs.cabal b/minio-hs.cabal
index f0c53d4..85ad26f 100644
--- a/minio-hs.cabal
+++ b/minio-hs.cabal
@@ -46,12 +46,10 @@ library
   build-depends:       base >= 4.7 && < 5
                      , protolude >= 0.1.6
                      , aeson
-                     , async
                      , base64-bytestring
                      , bytestring
                      , case-insensitive
                      , conduit
-                     , conduit-combinators
                      , conduit-extra
                      , containers
                      , cryptonite
@@ -62,22 +60,19 @@ library
                      , http-client
                      , http-conduit
                      , http-types
-                     , lifted-async
-                     , lifted-base
                      , memory
-                     , monad-control
                      , resourcet
                      , text
                      , text-format
                      , time
                      , transformers
-                     , transformers-base
-                     , vector
+                     , unliftio
+                     , unliftio-core
                      , xml-conduit
   default-language:    Haskell2010
-  default-extensions:  FlexibleContexts
+  default-extensions:  BangPatterns
+                     , FlexibleContexts
                      , FlexibleInstances
-                     , BangPatterns
                      , MultiParamTypeClasses
                      , MultiWayIf
                      , NoImplicitPrelude
@@ -100,12 +95,12 @@ test-suite minio-hs-live-server-test
   default-extensions:  BangPatterns
                      , FlexibleContexts
                      , FlexibleInstances
-                     , OverloadedStrings
-                     , NoImplicitPrelude
                      , MultiParamTypeClasses
                      , MultiWayIf
-                     , ScopedTypeVariables
+                     , NoImplicitPrelude
+                     , OverloadedStrings
                      , RankNTypes
+                     , ScopedTypeVariables
                      , TupleSections
                      , TypeFamilies
   other-modules:       Lib.Prelude
@@ -133,12 +128,10 @@ test-suite minio-hs-live-server-test
                      , minio-hs
                      , protolude >= 0.1.6
                      , aeson
-                     , async
                      , base64-bytestring
                      , bytestring
                      , case-insensitive
                      , conduit
-                     , conduit-combinators
                      , conduit-extra
                      , containers
                      , cryptonite
@@ -150,10 +143,7 @@ test-suite minio-hs-live-server-test
                      , http-client
                      , http-conduit
                      , http-types
-                     , lifted-async
-                     , lifted-base
                      , memory
-                     , monad-control
                      , QuickCheck
                      , resourcet
                      , tasty
@@ -165,8 +155,8 @@ test-suite minio-hs-live-server-test
                      , text-format
                      , time
                      , transformers
-                     , transformers-base
-                     , vector
+                     , unliftio
+                     , unliftio-core
                      , xml-conduit
   if !flag(live-test)
     buildable: False
@@ -179,12 +169,10 @@ test-suite minio-hs-test
                      , minio-hs
                      , protolude >= 0.1.6
                      , aeson
-                     , async
                      , base64-bytestring
                      , bytestring
                      , case-insensitive
                      , conduit
-                     , conduit-combinators
                      , conduit-extra
                      , containers
                      , cryptonite
@@ -192,14 +180,10 @@ test-suite minio-hs-test
                      , data-default
                      , directory
                      , exceptions
-                     , filepath
                      , http-client
                      , http-conduit
                      , http-types
-                     , lifted-async
-                     , lifted-base
                      , memory
-                     , monad-control
                      , QuickCheck
                      , resourcet
                      , tasty
@@ -211,20 +195,20 @@ test-suite minio-hs-test
                      , text-format
                      , time
                      , transformers
-                     , transformers-base
-                     , vector
+                     , unliftio
+                     , unliftio-core
                      , xml-conduit
   ghc-options:         -Wall -threaded -rtsopts -with-rtsopts=-N
   default-language:    Haskell2010
   default-extensions:  BangPatterns
                      , FlexibleContexts
                      , FlexibleInstances
-                     , OverloadedStrings
-                     , NoImplicitPrelude
                      , MultiParamTypeClasses
                      , MultiWayIf
-                     , ScopedTypeVariables
+                     , NoImplicitPrelude
+                     , OverloadedStrings
                      , RankNTypes
+                     , ScopedTypeVariables
                      , TupleSections
                      , TypeFamilies
   other-modules:       Lib.Prelude
diff --git a/src/Network/Minio.hs b/src/Network/Minio.hs
index 73fa61b..f9c023d 100644
--- a/src/Network/Minio.hs
+++ b/src/Network/Minio.hs
@@ -179,7 +179,6 @@ import qualified Data.Conduit             as C
 import qualified Data.Conduit.Binary      as CB
 import qualified Data.Conduit.Combinators as CC
 import           Data.Default             (def)
-import qualified Data.Map                 as Map
 
 import           Lib.Prelude
 
@@ -189,6 +188,7 @@ import           Network.Minio.Errors
 import           Network.Minio.ListOps
 import           Network.Minio.PutObject
 import           Network.Minio.S3API
+import           Network.Minio.Utils
 
 -- | Lists buckets.
 listBuckets :: Minio [BucketInfo]
@@ -200,7 +200,7 @@ listBuckets = getService
 fGetObject :: Bucket -> Object -> FilePath -> GetObjectOptions -> Minio ()
 fGetObject bucket object fp opts = do
   src <- getObject bucket object opts
-  src C.$$+- CB.sinkFileCautious fp
+  C.connect src $ CB.sinkFileCautious fp
 
 -- | Upload the given file to the given object.
 fPutObject :: Bucket -> Object -> FilePath
@@ -212,7 +212,7 @@ fPutObject bucket object f opts =
 -- known; this helps the library select optimal part sizes to perform
 -- a multipart upload. If not specified, it is assumed that the object
 -- can be potentially 5TiB and selects multipart sizes appropriately.
-putObject :: Bucket -> Object -> C.Producer Minio ByteString
+putObject :: Bucket -> Object -> C.ConduitM () ByteString Minio ()
           -> Maybe Int64 -> PutObjectOptions -> Minio ()
 putObject bucket object src sizeMay opts =
   void $ putObjectInternal bucket object opts $ ODStream src sizeMay
@@ -223,15 +223,18 @@ putObject bucket object src sizeMay opts =
 -- copy operation if the new object is to be greater than 5GiB in
 -- size.
 copyObject :: DestinationInfo -> SourceInfo -> Minio ()
-copyObject dstInfo srcInfo = void $ copyObjectInternal (dstBucket dstInfo) (dstObject dstInfo) srcInfo
+copyObject dstInfo srcInfo = void $ copyObjectInternal (dstBucket dstInfo)
+                             (dstObject dstInfo) srcInfo
 
 -- | Remove an object from the object store.
 removeObject :: Bucket -> Object -> Minio ()
 removeObject = deleteObject
 
 -- | Get an object from the object store as a resumable source (conduit).
-getObject :: Bucket -> Object -> GetObjectOptions -> Minio (C.ResumableSource Minio ByteString)
-getObject bucket object opts = snd <$> getObject' bucket object [] (gooToHeaders opts)
+getObject :: Bucket -> Object -> GetObjectOptions
+          -> Minio (C.ConduitM () ByteString Minio ())
+getObject bucket object opts = snd <$> getObject' bucket object []
+                               (gooToHeaders opts)
 
 -- | Get an object's metadata from the object store.
 statObject :: Bucket -> Object -> Minio ObjectInfo
@@ -245,21 +248,21 @@ makeBucket :: Bucket -> Maybe Region -> Minio ()
 makeBucket bucket regionMay = do
   region <- maybe (asks $ connectRegion . mcConnInfo) return regionMay
   putBucket bucket region
-  modify (Map.insert bucket region)
+  addToRegionCache bucket region
 
 -- | Removes a bucket from the object store.
 removeBucket :: Bucket -> Minio ()
 removeBucket bucket = do
   deleteBucket bucket
-  modify (Map.delete bucket)
+  deleteFromRegionCache bucket
 
 -- | Query the object store if a given bucket is present.
 bucketExists :: Bucket -> Minio Bool
 bucketExists = headBucket
 
-
 -- | Removes an ongoing multipart upload of an object.
 removeIncompleteUpload :: Bucket -> Object -> Minio ()
 removeIncompleteUpload bucket object = do
-  uploads <- listIncompleteUploads bucket (Just object) False C.$$ CC.sinkList
+  uploads <- C.runConduit $ listIncompleteUploads bucket (Just object) False
+             C..| CC.sinkList
   mapM_ (abortMultipartUpload bucket object) (uiUploadId <$> uploads)
diff --git a/src/Network/Minio/API.hs b/src/Network/Minio/API.hs
index c34d3cb..abf6d27 100644
--- a/src/Network/Minio/API.hs
+++ b/src/Network/Minio/API.hs
@@ -15,8 +15,7 @@
 --
 
 module Network.Minio.API
-  (
-    connect
+  ( connect
   , RequestInfo(..)
   , runMinio
   , executeRequest
@@ -86,10 +85,10 @@ getLocation bucket = do
 discoverRegion :: RequestInfo -> Minio (Maybe Region)
 discoverRegion ri = runMaybeT $ do
   bucket <- MaybeT $ return $ riBucket ri
-  regionMay <- gets (Map.lookup bucket)
+  regionMay <- lift $ lookupRegionCache bucket
   maybe (do
             l <- lift $ getLocation bucket
-            modify $ Map.insert bucket l
+            lift $ addToRegionCache bucket l
             return l
         ) return regionMay
 
@@ -161,7 +160,7 @@ executeRequest ri = do
 
 
 mkStreamRequest :: RequestInfo
-                -> Minio (Response (C.ResumableSource Minio ByteString))
+                -> Minio (Response (C.ConduitM () ByteString Minio ()))
 mkStreamRequest ri = do
   req <- buildRequest ri
   mgr <- asks mcConnManager
diff --git a/src/Network/Minio/Data.hs b/src/Network/Minio/Data.hs
index eaffd84..36cf9b0 100644
--- a/src/Network/Minio/Data.hs
+++ b/src/Network/Minio/Data.hs
@@ -18,9 +18,11 @@
 {-# LANGUAGE TypeFamilies               #-}
 module Network.Minio.Data where
 
-import           Control.Monad.Base
+import           Control.Concurrent.MVar      (MVar)
+import qualified Control.Concurrent.MVar      as M
 import qualified Control.Monad.Catch          as MC
-import           Control.Monad.Trans.Control
+import           Control.Monad.IO.Unlift      (MonadUnliftIO, UnliftIO (..),
+                                               askUnliftIO, withUnliftIO)
 import           Control.Monad.Trans.Resource
 
 import qualified Data.ByteString              as B
@@ -195,7 +197,7 @@ data PutObjectOptions = PutObjectOptions {
   , pooStorageClass       :: Maybe Text
   , pooUserMetadata       :: [(Text, Text)]
   , pooNumThreads         :: Maybe Word
-    } deriving (Show, Eq)
+  } deriving (Show, Eq)
 
 -- Provide a default instance
 instance Default PutObjectOptions where
@@ -498,7 +500,7 @@ type UrlExpiry = Int
 type RegionMap = Map.Map Bucket Region
 
 newtype Minio a = Minio {
-  unMinio :: ReaderT MinioConn (StateT RegionMap (ResourceT IO)) a
+  unMinio :: ReaderT MinioConn (ResourceT IO) a
   }
   deriving (
       Functor
@@ -506,38 +508,38 @@ newtype Minio a = Minio {
     , Monad
     , MonadIO
     , MonadReader MinioConn
-    , MonadState RegionMap
     , MonadThrow
     , MonadCatch
-    , MonadBase IO
     , MonadResource
     )
 
-instance MonadBaseControl IO Minio where
-  type StM Minio a = (a, RegionMap)
-  liftBaseWith f = Minio $ liftBaseWith $ \q -> f (q . unMinio)
-  restoreM = Minio . restoreM
+instance MonadUnliftIO Minio where
+  askUnliftIO = Minio $ ReaderT $ \r ->
+                withUnliftIO $ \u ->
+                return (UnliftIO (unliftIO u . flip runReaderT r . unMinio))
 
 -- | MinioConn holds connection info and a connection pool
-data MinioConn = MinioConn {
-    mcConnInfo    :: ConnectInfo
+data MinioConn = MinioConn
+  { mcConnInfo    :: ConnectInfo
   , mcConnManager :: NC.Manager
+  , mcRegionMap   :: MVar RegionMap
   }
 
 -- | Takes connection information and returns a connection object to
 -- be passed to 'runMinio'
 connect :: ConnectInfo -> IO MinioConn
 connect ci = do
-  let settings = bool defaultManagerSettings NC.tlsManagerSettings $
-        connectIsSecure ci
+  let settings | connectIsSecure ci = NC.tlsManagerSettings
+               | otherwise = defaultManagerSettings
   mgr <- NC.newManager settings
-  return $ MinioConn ci mgr
+  rMapMVar <- M.newMVar Map.empty
+  return $ MinioConn ci mgr rMapMVar
 
 -- | Run the Minio action and return the result or an error.
 runMinio :: ConnectInfo -> Minio a -> IO (Either MinioErr a)
 runMinio ci m = do
   conn <- liftIO $ connect ci
-  runResourceT . flip evalStateT Map.empty . flip runReaderT conn . unMinio $
+  runResourceT . flip runReaderT conn . unMinio $
     fmap Right m `MC.catches`
     [ MC.Handler handlerServiceErr
     , MC.Handler handlerHE
diff --git a/src/Network/Minio/Data/Crypto.hs b/src/Network/Minio/Data/Crypto.hs
index da47265..b3d9283 100644
--- a/src/Network/Minio/Data/Crypto.hs
+++ b/src/Network/Minio/Data/Crypto.hs
@@ -28,37 +28,38 @@ module Network.Minio.Data.Crypto
   , digestToBase16
   ) where
 
-import           Crypto.Hash (SHA256(..), MD5(..), hashWith, Digest)
-import           Crypto.Hash.Conduit (sinkHash)
-import           Crypto.MAC.HMAC (hmac, HMAC)
-import           Data.ByteArray (ByteArrayAccess, convert)
-import           Data.ByteArray.Encoding (convertToBase, Base(Base16))
-import qualified Data.Conduit as C
+import           Crypto.Hash             (Digest, MD5 (..), SHA256 (..),
+                                          hashWith)
+import           Crypto.Hash.Conduit     (sinkHash)
+import           Crypto.MAC.HMAC         (HMAC, hmac)
+import           Data.ByteArray          (ByteArrayAccess, convert)
+import           Data.ByteArray.Encoding (Base (Base16), convertToBase)
+import qualified Data.Conduit            as C
 
 import           Lib.Prelude
 
 hashSHA256 :: ByteString -> ByteString
 hashSHA256 = digestToBase16 . hashWith SHA256
 
-hashSHA256FromSource :: Monad m => C.Producer m ByteString -> m ByteString
+hashSHA256FromSource :: Monad m => C.ConduitM () ByteString m () -> m ByteString
 hashSHA256FromSource src = do
-  digest <- src C.$$ sinkSHA256Hash
+  digest <- C.connect src sinkSHA256Hash
   return $ digestToBase16 digest
   where
     -- To help with type inference
-    sinkSHA256Hash :: Monad m => C.Consumer ByteString m (Digest SHA256)
+    sinkSHA256Hash :: Monad m => C.ConduitM ByteString Void m (Digest SHA256)
     sinkSHA256Hash = sinkHash
 
 hashMD5 :: ByteString -> ByteString
 hashMD5 = digestToBase16 . hashWith MD5
 
-hashMD5FromSource :: Monad m => C.Producer m ByteString -> m ByteString
+hashMD5FromSource :: Monad m => C.ConduitM () ByteString m () -> m ByteString
 hashMD5FromSource src = do
-  digest <- src C.$$ sinkMD5Hash
+  digest <- C.connect src sinkMD5Hash
   return $ digestToBase16 digest
   where
     -- To help with type inference
-    sinkMD5Hash :: Monad m => C.Consumer ByteString m (Digest MD5)
+    sinkMD5Hash :: Monad m => C.ConduitM ByteString Void m (Digest MD5)
     sinkMD5Hash = sinkHash
 
 hmacSHA256 :: ByteString -> ByteString -> HMAC SHA256
diff --git a/src/Network/Minio/ListOps.hs b/src/Network/Minio/ListOps.hs
index 3e90eb6..2168dd3 100644
--- a/src/Network/Minio/ListOps.hs
+++ b/src/Network/Minio/ListOps.hs
@@ -16,9 +16,9 @@
 
 module Network.Minio.ListOps where
 
-import qualified Data.Conduit as C
+import qualified Data.Conduit             as C
 import qualified Data.Conduit.Combinators as CC
-import qualified Data.Conduit.List as CL
+import qualified Data.Conduit.List        as CL
 
 import           Lib.Prelude
 
@@ -27,10 +27,10 @@ import           Network.Minio.S3API
 
 -- | List objects in a bucket matching the given prefix. If recurse is
 -- set to True objects matching prefix are recursively listed.
-listObjects :: Bucket -> Maybe Text -> Bool -> C.Producer Minio ObjectInfo
+listObjects :: Bucket -> Maybe Text -> Bool -> C.ConduitM () ObjectInfo Minio ()
 listObjects bucket prefix recurse = loop Nothing
   where
-    loop :: Maybe Text -> C.Producer Minio ObjectInfo
+    loop :: Maybe Text -> C.ConduitM () ObjectInfo Minio ()
     loop nextToken = do
       let
         delimiter = bool (Just "/") Nothing recurse
@@ -42,10 +42,11 @@ listObjects bucket prefix recurse = loop Nothing
 
 -- | List objects in a bucket matching the given prefix. If recurse is
 -- set to True objects matching prefix are recursively listed.
-listObjectsV1 :: Bucket -> Maybe Text -> Bool -> C.Producer Minio ObjectInfo
+listObjectsV1 :: Bucket -> Maybe Text -> Bool
+              -> C.ConduitM () ObjectInfo Minio ()
 listObjectsV1 bucket prefix recurse = loop Nothing
   where
-    loop :: Maybe Text -> C.Producer Minio ObjectInfo
+    loop :: Maybe Text -> C.ConduitM () ObjectInfo Minio ()
     loop nextMarker = do
       let
         delimiter = bool (Just "/") Nothing recurse
@@ -59,10 +60,10 @@ listObjectsV1 bucket prefix recurse = loop Nothing
 -- recurse is set to True incomplete uploads for the given prefix are
 -- recursively listed.
 listIncompleteUploads :: Bucket -> Maybe Text -> Bool
-                      -> C.Producer Minio UploadInfo
+                      -> C.ConduitM () UploadInfo Minio ()
 listIncompleteUploads bucket prefix recurse = loop Nothing Nothing
   where
-    loop :: Maybe Text -> Maybe Text -> C.Producer Minio UploadInfo
+    loop :: Maybe Text -> Maybe Text -> C.ConduitM () UploadInfo Minio ()
     loop nextKeyMarker nextUploadIdMarker = do
       let
         delimiter = bool (Just "/") Nothing recurse
@@ -71,7 +72,8 @@ listIncompleteUploads bucket prefix recurse = loop Nothing Nothing
              nextKeyMarker nextUploadIdMarker Nothing
 
       aggrSizes <- lift $ forM (lurUploads res) $ \(uKey, uId, _) -> do
-            partInfos <- listIncompleteParts bucket uKey uId C.$$ CC.sinkList
+            partInfos <- C.runConduit $ listIncompleteParts bucket uKey uId
+                    C..| CC.sinkList
             return $ foldl (\sizeSofar p -> opiSize p + sizeSofar) 0 partInfos
 
       CL.sourceList $
@@ -86,10 +88,10 @@ listIncompleteUploads bucket prefix recurse = loop Nothing Nothing
 -- | List object parts of an ongoing multipart upload for given
 -- bucket, object and uploadId.
 listIncompleteParts :: Bucket -> Object -> UploadId
-                    -> C.Producer Minio ObjectPartInfo
+                    -> C.ConduitM () ObjectPartInfo Minio ()
 listIncompleteParts bucket object uploadId = loop Nothing
   where
-    loop :: Maybe Text -> C.Producer Minio ObjectPartInfo
+    loop :: Maybe Text -> C.ConduitM () ObjectPartInfo Minio ()
     loop nextPartMarker = do
       res <- lift $ listIncompleteParts' bucket object uploadId Nothing
              nextPartMarker
diff --git a/src/Network/Minio/PutObject.hs b/src/Network/Minio/PutObject.hs
index f34c6c4..d3601b7 100644
--- a/src/Network/Minio/PutObject.hs
+++ b/src/Network/Minio/PutObject.hs
@@ -46,9 +46,14 @@ import           Network.Minio.Utils
 -- For streams also, a size may be provided. This is useful to limit
 -- the input - if it is not provided, upload will continue until the
 -- stream ends or the object reaches `maxObjectsize` size.
-data ObjectData m =
-  ODFile FilePath (Maybe Int64) -- ^ Takes filepath and optional size.
-  | ODStream (C.Producer m ByteString) (Maybe Int64) -- ^ Pass size in bytes as maybe if known.
+data ObjectData m
+  = ODFile FilePath (Maybe Int64) -- ^ Takes filepath and optional
+                                  -- size.
+  | ODStream (C.ConduitM () ByteString m ()) (Maybe Int64) -- ^ Pass
+                                                           -- size
+                                                           -- (bytes)
+                                                           -- if
+                                                           -- known.
 
 -- | Put an object from ObjectData. This high-level API handles
 -- objects of all sizes, and even if the object size is unknown.
@@ -108,7 +113,7 @@ parallelMultipartUpload b o opts filePath size = do
 -- | Upload multipart object from conduit source sequentially
 sequentialMultipartUpload :: Bucket -> Object -> PutObjectOptions
                           -> Maybe Int64
-                          -> C.Producer Minio ByteString
+                          -> C.ConduitM () ByteString Minio ()
                           -> Minio ETag
 sequentialMultipartUpload b o opts sizeMay src = do
   -- get a new upload id.
@@ -117,11 +122,12 @@ sequentialMultipartUpload b o opts sizeMay src = do
   -- upload parts in loop
   let partSizes = selectPartSizes $ maybe maxObjectSize identity sizeMay
       (pnums, _, sizes) = List.unzip3 partSizes
-  uploadedParts <- src
+  uploadedParts <- C.runConduit
+                 $ src
               C..| chunkBSConduit sizes
               C..| CL.map PayloadBS
               C..| uploadPart' uploadId pnums
-              C.$$ CC.sinkList
+              C..| CC.sinkList
 
   -- complete multipart upload
   completeMultipartUpload b o uploadId uploadedParts
diff --git a/src/Network/Minio/S3API.hs b/src/Network/Minio/S3API.hs
index fe6428e..1d55369 100644
--- a/src/Network/Minio/S3API.hs
+++ b/src/Network/Minio/S3API.hs
@@ -114,7 +114,7 @@ getService = do
 -- | GET an object from the service and return the response headers
 -- and a conduit source for the object content
 getObject' :: Bucket -> Object -> HT.Query -> [HT.Header]
-           -> Minio ([HT.Header], C.ResumableSource Minio ByteString)
+           -> Minio ([HT.Header], C.ConduitM () ByteString Minio ())
 getObject' bucket object queryParams headers = do
   resp <- mkStreamRequest reqInfo
   return (NC.responseHeaders resp, NC.responseBody resp)
diff --git a/src/Network/Minio/Utils.hs b/src/Network/Minio/Utils.hs
index 710e853..5051eb3 100644
--- a/src/Network/Minio/Utils.hs
+++ b/src/Network/Minio/Utils.hs
@@ -16,71 +16,71 @@
 
 module Network.Minio.Utils where
 
-import qualified Control.Concurrent.Async.Lifted as A
-import qualified Control.Concurrent.QSem.Lifted as Q
-import qualified Control.Exception.Lifted as ExL
-import qualified Control.Monad.Catch as MC
-import qualified Control.Monad.Trans.Resource as R
-
-import qualified Data.Map        as Map
-import qualified Data.ByteString as B
-import qualified Data.ByteString.Lazy as LB
-import           Data.CaseInsensitive (mk)
-import           Data.CaseInsensitive (original)
-import qualified Data.Conduit as C
-import qualified Data.Conduit.Binary as CB
-import qualified Data.List as List
-import qualified Data.Text as T
-import           Data.Text.Encoding.Error (lenientDecode)
-import           Data.Text.Read (decimal)
-import           Data.Time
-import           Network.HTTP.Conduit (Response)
-import qualified Network.HTTP.Conduit as NC
-import qualified Network.HTTP.Types as HT
-import qualified Network.HTTP.Types.Header as Hdr
-import qualified System.IO as IO
-
+import qualified Control.Monad.Catch           as MC
+import           Control.Monad.IO.Unlift       (MonadUnliftIO)
+import qualified Control.Monad.Trans.Resource  as R
+import qualified Data.ByteString               as B
+import qualified Data.ByteString.Lazy          as LB
+import           Data.CaseInsensitive          (mk, original)
+import qualified Data.Conduit                  as C
+import qualified Data.Conduit.Binary           as CB
+import qualified Data.List                     as List
+import qualified Data.Map                      as Map
+import qualified Data.Text                     as T
+import           Data.Text.Encoding.Error      (lenientDecode)
+import           Data.Text.Read                (decimal)
+import           Data.Time                     (defaultTimeLocale, parseTimeM,
+                                                rfc822DateFormat)
+import           Network.HTTP.Conduit          (Response)
+import qualified Network.HTTP.Conduit          as NC
+import qualified Network.HTTP.Types            as HT
+import qualified Network.HTTP.Types.Header     as Hdr
+import qualified System.IO                     as IO
+import qualified UnliftIO.Async                as A
+import qualified UnliftIO.Exception            as UEx
+import qualified UnliftIO.MVar                 as UM
+import qualified UnliftIO.STM                  as U
 
 import           Lib.Prelude
 
 import           Network.Minio.Data
 import           Network.Minio.Data.ByteString
-import           Network.Minio.XmlParser (parseErrResponse)
+import           Network.Minio.XmlParser       (parseErrResponse)
 
-allocateReadFile :: (R.MonadResource m, R.MonadResourceBase m, MonadCatch m)
+allocateReadFile :: (MonadUnliftIO m, R.MonadResource m, MonadCatch m)
                  => FilePath -> m (R.ReleaseKey, Handle)
 allocateReadFile fp = do
   (rk, hdlE) <- R.allocate (openReadFile fp) cleanup
   either (\(e :: IOException) -> throwM e) (return . (rk,)) hdlE
   where
-    openReadFile f = ExL.try $ IO.openBinaryFile f IO.ReadMode
+    openReadFile f = UEx.try $ IO.openBinaryFile f IO.ReadMode
     cleanup = either (const $ return ()) IO.hClose
 
 -- | Queries the file size from the handle. Catches any file operation
 -- exceptions and returns Nothing instead.
-getFileSize :: (R.MonadResourceBase m, R.MonadResource m)
+getFileSize :: (MonadUnliftIO m, R.MonadResource m)
             => Handle -> m (Maybe Int64)
 getFileSize h = do
   resE <- liftIO $ try $ fromIntegral <$> IO.hFileSize h
   case resE of
     Left (_ :: IOException) -> return Nothing
-    Right s -> return $ Just s
+    Right s                 -> return $ Just s
 
 -- | Queries if handle is seekable. Catches any file operation
 -- exceptions and return False instead.
-isHandleSeekable :: (R.MonadResource m, R.MonadResourceBase m)
+isHandleSeekable :: (R.MonadResource m, MonadUnliftIO m)
                => Handle -> m Bool
 isHandleSeekable h = do
   resE <- liftIO $ try $ IO.hIsSeekable h
   case resE of
     Left (_ :: IOException) -> return False
-    Right v -> return v
+    Right v                 -> return v
 
 -- | Helper function that opens a handle to the filepath and performs
 -- the given action on it. Exceptions of type MError are caught and
 -- returned - both during file handle allocation and when the action
 -- is run.
-withNewHandle :: (R.MonadResourceBase m, R.MonadResource m, MonadCatch m)
+withNewHandle :: (MonadUnliftIO m, R.MonadResource m, MonadCatch m)
               => FilePath -> (Handle -> m a) -> m (Either IOException a)
 withNewHandle fp fileAction = do
   -- opening a handle can throw MError exception.
@@ -150,16 +150,17 @@ httpLbs req mgr = do
     contentTypeMay resp = lookupHeader Hdr.hContentType $
                           NC.responseHeaders resp
 
-http :: (R.MonadResourceBase m, R.MonadResource m)
+http :: (MonadUnliftIO m, MonadThrow m, R.MonadResource m)
      => NC.Request -> NC.Manager
-     -> m (Response (C.ResumableSource m ByteString))
+     -> m (Response (C.ConduitT () ByteString m ()))
 http req mgr = do
   respE <- tryHttpEx $ NC.http req mgr
   resp <- either throwM return respE
   unless (isSuccessStatus $ NC.responseStatus resp) $
     case contentTypeMay resp of
       Just "application/xml" -> do
-        respBody <- NC.responseBody resp C.$$+- CB.sinkLbs
+        respBody <- C.connect (NC.responseBody resp) CB.sinkLbs
+        --respBody <- C.unsealConduitT (NC.responseBody resp) C.$$+- CB.sinkLbs
         sErr <- parseErrResponse respBody
         throwM sErr
 
@@ -171,23 +172,34 @@ http req mgr = do
 
   return resp
   where
-    tryHttpEx :: (R.MonadResourceBase m) => m a
+    tryHttpEx :: (MonadUnliftIO m) => m a
               -> m (Either NC.HttpException a)
-    tryHttpEx = ExL.try
+    tryHttpEx = UEx.try
     contentTypeMay resp = lookupHeader Hdr.hContentType $ NC.responseHeaders resp
 
 -- Similar to mapConcurrently but limits the number of threads that
 -- can run using a quantity semaphore.
-limitedMapConcurrently :: (MonadIO m, R.MonadBaseControl IO m)
+limitedMapConcurrently :: MonadUnliftIO m
                        => Int -> (t -> m a) -> [t] -> m [a]
+limitedMapConcurrently 0 _ _ = return []
 limitedMapConcurrently count act args = do
-  qSem <- liftIO $ Q.newQSem count
-  threads <- mapM (A.async . wThread qSem) args
+  t' <- U.newTVarIO count
+  threads <- mapM (A.async . wThread t') args
   mapM A.wait threads
   where
-    -- grab 1 unit from semaphore, run action and release it
-    wThread qs arg =
-      ExL.bracket_ (Q.waitQSem qs) (Q.signalQSem qs) $ act arg
+    wThread t arg =
+      UEx.bracket_ (waitSem t) (signalSem t) $ act arg
+
+    -- quantity semaphore implementation using TVar
+    waitSem t = U.atomically $ do
+      v <- U.readTVar t
+      if v > 0
+      then U.writeTVar t (v-1)
+      else U.retrySTM
+
+    signalSem t = U.atomically $ do
+      v <- U.readTVar t
+      U.writeTVar t (v+1)
 
 -- helper function to 'drop' empty optional parameter.
 mkQuery :: Text -> Maybe Text -> Maybe (Text, Text)
@@ -199,7 +211,7 @@ mkOptionalParams :: [(Text, Maybe Text)] -> HT.Query
 mkOptionalParams params = HT.toQuery $ uncurry  mkQuery <$> params
 
 chunkBSConduit :: (Monad m, Integral a)
-               => [a] -> C.Conduit ByteString m ByteString
+               => [a] -> C.ConduitM ByteString ByteString m ()
 chunkBSConduit s = loop 0 [] s
   where
     loop _ _ [] = return ()
@@ -231,3 +243,19 @@ selectPartSizes size = uncurry (List.zip3 [1..]) $
       | st > sz = []
       | st + m >= sz = [(st, sz - st)]
       | otherwise = (st, m) : loop (st + m) sz
+
+lookupRegionCache :: Bucket -> Minio (Maybe Region)
+lookupRegionCache b = do
+    rMVar <- asks mcRegionMap
+    rMap <- UM.readMVar rMVar
+    return $ Map.lookup b rMap
+
+addToRegionCache :: Bucket -> Region -> Minio ()
+addToRegionCache b region = do
+    rMVar <- asks mcRegionMap
+    UM.modifyMVar_ rMVar $ return . Map.insert b region
+
+deleteFromRegionCache :: Bucket -> Minio ()
+deleteFromRegionCache b = do
+    rMVar <- asks mcRegionMap
+    UM.modifyMVar_ rMVar $ return . Map.delete b
diff --git a/stack.yaml b/stack.yaml
index aed9f1c..7a77534 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -15,7 +15,7 @@
 # resolver:
 #  name: custom-snapshot
 #  location: "./custom-snapshot.yaml"
-resolver: lts-9.1
+resolver: lts-11.1
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.
diff --git a/test/LiveServer.hs b/test/LiveServer.hs
index 4ace2c1..4195ef2 100644
--- a/test/LiveServer.hs
+++ b/test/LiveServer.hs
@@ -19,15 +19,10 @@ import           Test.Tasty
 import           Test.Tasty.HUnit
 import           Test.Tasty.QuickCheck                 as QC
 
-import           Lib.Prelude
-
-import           System.Directory                      (getTemporaryDirectory)
-import qualified System.IO                             as SIO
-
 import qualified Control.Monad.Catch                   as MC
 import qualified Control.Monad.Trans.Resource          as R
 import qualified Data.ByteString                       as BS
-import           Data.Conduit                          (yield, ($$))
+import           Data.Conduit                          (yield)
 import qualified Data.Conduit                          as C
 import qualified Data.Conduit.Binary                   as CB
 import           Data.Conduit.Combinators              (sinkList)
@@ -39,7 +34,11 @@ import qualified Data.Time                             as Time
 import qualified Network.HTTP.Client.MultipartFormData as Form
 import qualified Network.HTTP.Conduit                  as NC
 import qualified Network.HTTP.Types                    as HT
+import           System.Directory                      (getTemporaryDirectory)
 import           System.Environment                    (lookupEnv)
+import qualified System.IO                             as SIO
+
+import           Lib.Prelude
 
 import           Network.Minio
 import           Network.Minio.Data
@@ -54,7 +53,7 @@ tests :: TestTree
 tests = testGroup "Tests" [liveServerUnitTests]
 
 -- conduit that generates random binary stream of given length
-randomDataSrc :: MonadIO m => Int64 -> C.Producer m ByteString
+randomDataSrc :: MonadIO m => Int64 -> C.ConduitM () ByteString m ()
 randomDataSrc s' = genBS s'
   where
     concatIt bs n = BS.concat $ replicate (fromIntegral q) bs ++
@@ -72,7 +71,7 @@ randomDataSrc s' = genBS s'
 mkRandFile :: R.MonadResource m => Int64 -> m FilePath
 mkRandFile size = do
   dir <- liftIO $ getTemporaryDirectory
-  randomDataSrc size C.$$ CB.sinkTempFile dir "miniohstest.random"
+  C.runConduit $ randomDataSrc size C..| CB.sinkTempFile dir "miniohstest.random"
 
 funTestBucketPrefix :: Text
 funTestBucketPrefix = "miniohstest-"
@@ -158,13 +157,14 @@ highLevelListingTest = funTestWithBucket "High-level listObjects Test" $
         \obj -> fPutObject bucket obj "/etc/lsb-release" def
 
       step "High-level listing of objects"
-      objects <- listObjects bucket Nothing True $$ sinkList
+      objects <- C.runConduit $ listObjects bucket Nothing True C..| sinkList
 
       liftIO $ assertEqual "Objects match failed!" (sort expectedObjects)
         (map oiObject objects)
 
       step "High-level listing of objects (version 1)"
-      objectsV1 <- listObjectsV1 bucket Nothing True $$ sinkList
+      objectsV1 <- C.runConduit $ listObjectsV1 bucket Nothing True C..|
+                   sinkList
 
       liftIO $ assertEqual "Objects match failed!" (sort expectedObjects)
         (map oiObject objectsV1)
@@ -181,7 +181,9 @@ highLevelListingTest = funTestWithBucket "High-level listObjects Test" $
         liftIO $ (T.length uid > 0) @? ("Got an empty multipartUpload Id.")
 
       step "High-level listing of incomplete multipart uploads"
-      uploads <- listIncompleteUploads bucket (Just "newmpupload") True $$ sinkList
+      uploads <- C.runConduit $
+                 listIncompleteUploads bucket (Just "newmpupload") True C..|
+                 sinkList
       liftIO $ length uploads @?= 10
 
       step "cleanup"
@@ -202,7 +204,8 @@ highLevelListingTest = funTestWithBucket "High-level listObjects Test" $
         putObjectPart bucket object uid pnum [] $ PayloadH h 0 mb5
 
       step "fetch list parts"
-      incompleteParts <- listIncompleteParts bucket object uid $$ sinkList
+      incompleteParts <- C.runConduit $ listIncompleteParts bucket object uid
+                         C..| sinkList
       liftIO $ length incompleteParts @?= 10
 
       step "cleanup"
@@ -318,7 +321,8 @@ liveServerUnitTests = testGroup "Unit tests against a live server"
 
       step "remove ongoing upload"
       removeIncompleteUpload bucket object
-      uploads <- listIncompleteUploads bucket (Just object) False C.$$ sinkList
+      uploads <- C.runConduit $ listIncompleteUploads bucket (Just object) False
+                 C..| sinkList
       liftIO $ (null uploads) @? "removeIncompleteUploads didn't complete successfully"
 
   , funTestWithBucket "putObject contentType tests" $ \step bucket -> do
@@ -345,11 +349,11 @@ liveServerUnitTests = testGroup "Unit tests against a live server"
         }
 
       oiCE <- headObject bucket object
-      let m = oiMetadata oiCE
+      let m' = oiMetadata oiCE
 
       step "Validate content-encoding"
       liftIO $ assertEqual "Content-Encoding did not match" (Just "identity")
-        (Map.lookup "Content-Encoding" m)
+        (Map.lookup "Content-Encoding" m')
 
       step "Cleanup actions"
 
@@ -475,8 +479,8 @@ liveServerUnitTests = testGroup "Unit tests against a live server"
       void $ completeMultipartUpload bucket copyObj uid parts
 
       step "verify copied object size"
-      oi <- headObject bucket copyObj
-      let s' = oiSize oi
+      oi' <- headObject bucket copyObj
+      let s' = oiSize oi'
 
       liftIO $ (s' == mb15) @? "Size failed to match"
 
@@ -491,8 +495,8 @@ liveServerUnitTests = testGroup "Unit tests against a live server"
 
       step "Prepare"
       forM_ (zip srcs sizes) $ \(src, size) -> do
-        inputFile <- mkRandFile size
-        fPutObject bucket src inputFile def
+        inputFile' <- mkRandFile size
+        fPutObject bucket src inputFile' def
 
       step "make small and large object copy"
       forM_ (zip copyObjs srcs) $ \(cp, src) ->
@@ -510,8 +514,8 @@ liveServerUnitTests = testGroup "Unit tests against a live server"
           size = 15 * 1024 * 1024
 
       step "Prepare"
-      inputFile <- mkRandFile size
-      fPutObject bucket src inputFile def
+      inputFile' <- mkRandFile size
+      fPutObject bucket src inputFile' def
 
       step "copy last 10MiB of object"
       copyObject def { dstBucket = bucket, dstObject = copyObj } def{
@@ -579,18 +583,18 @@ basicTests = funTestWithBucket "Basic tests" $ \step bucket -> do
         _        -> return ()
 
       step "fGetObject an object with no matching etag, check for exception"
-      resE <- MC.try $ fGetObject bucket "lsb-release" outFile def{
+      resE1 <- MC.try $ fGetObject bucket "lsb-release" outFile def{
         gooIfMatch = (Just "invalid-etag")
         }
-      case resE of
+      case resE1 of
         Left exn -> liftIO $ exn @?= ServiceErr "PreconditionFailed" "At least one of the pre-conditions you specified did not hold"
         _        -> return ()
 
       step "fGetObject an object with no valid range, check for exception"
-      resE <- MC.try $ fGetObject bucket "lsb-release" outFile def{
+      resE2 <- MC.try $ fGetObject bucket "lsb-release" outFile def{
         gooRange = (Just $ HT.ByteRangeFromTo 100 200)
         }
-      case resE of
+      case resE2 of
           Left exn -> liftIO $ exn @?= ServiceErr "InvalidRange" "The requested range is not satisfiable"
           _        -> return ()
 
@@ -600,8 +604,8 @@ basicTests = funTestWithBucket "Basic tests" $ \step bucket -> do
         }
 
       step "fGetObject a non-existent object and check for NoSuchKey exception"
-      resE <- MC.try $ fGetObject bucket "noSuchKey" outFile def
-      case resE of
+      resE3 <- MC.try $ fGetObject bucket "noSuchKey" outFile def
+      case resE3 of
         Left exn -> liftIO $ exn @?= NoSuchKey
         _        -> return ()
 
@@ -658,7 +662,7 @@ presignedUrlFunTest = funTestWithBucket "presigned Url tests" $
       "presigned GET failed"
 
     -- read content from file to compare with response above
-    bs <- CB.sourceFile inputFile $$ CB.sinkLbs
+    bs <- C.runConduit $ CB.sourceFile inputFile C..| CB.sinkLbs
     liftIO $ (bs == NC.responseBody getResp) @?
       "presigned put and get got mismatched data"
 
@@ -693,7 +697,7 @@ presignedUrlFunTest = funTestWithBucket "presigned Url tests" $
       "presigned GET failed (presignedGetObjectUrl)"
 
     -- read content from file to compare with response above
-    bs2 <- CB.sourceFile testFile $$ CB.sinkLbs
+    bs2 <- C.runConduit $ CB.sourceFile testFile C..| CB.sinkLbs
     liftIO $ (bs2 == NC.responseBody getResp2) @?
       "presigned put and get got mismatched data (presigned*Url)"