diff --git a/CHANGELOG.md b/CHANGELOG.md
index 45302b3..52f388a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,12 @@
 Changelog
 ==========
 
+## Version 1.5.0
+
+* Switch to faster map data type - all previous usage of
+  Data.Map.Strict and Data.Set is replaced with Data.HashMap.Strict
+  and Data.HashSet.
+
 ## Version 1.4.0
 
 * Expose runMinioRes and runMinioResWith (#129)
diff --git a/docs/API.md b/docs/API.md
index d8ef3f7..d90d60c 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -247,12 +247,13 @@ __Return Value__
 
 __ObjectInfo record type__
 
-| Field       | Type                        | Description                      |
-|:------------|:----------------------------|:---------------------------------|
-| `oiObject`  | _Object_ (alias for `Text`) | Name of object                   |
-| `oiModTime` | _UTCTime_                   | Last modified time of the object |
-| `oiETag`    | _ETag_ (alias for `Text`)   | ETag of the object               |
-| `oiSize`    | _Int64_                     | Size of the object in bytes      |
+| Field        | Type                        | Description                          |
+|:-------------|:----------------------------|:-------------------------------------|
+| `oiObject`   | _Object_ (alias for `Text`) | Name of object                       |
+| `oiModTime`  | _UTCTime_                   | Last modified time of the object     |
+| `oiETag`     | _ETag_ (alias for `Text`)   | ETag of the object                   |
+| `oiSize`     | _Int64_                     | Size of the object in bytes          |
+| `oiMetadata` | _HashMap Text Text_         | Map of key-value user-metadata pairs |
 
 __Example__
 
@@ -928,7 +929,7 @@ main = do
 ```
 
 <a name="presignedPostPolicy"></a>
-### presignedPostPolicy :: PostPolicy -> Minio (ByteString, Map.Map Text ByteString)
+### presignedPostPolicy :: PostPolicy -> Minio (ByteString, HashMap Text ByteString)
 
 Generate a presigned URL and POST policy to upload files via a POST
 request. This is intended for browser uploads and generates form data
@@ -965,7 +966,7 @@ import Network.Minio
 
 import qualified Data.ByteString       as B
 import qualified Data.ByteString.Char8 as Char8
-import qualified Data.Map.Strict       as Map
+import qualified Data.HashMap.Strict   as H
 import qualified Data.Text.Encoding    as Enc
 import qualified Data.Time             as Time
 
@@ -1005,7 +1006,7 @@ main = do
         let
           formFn (k, v) = B.concat ["-F ", Enc.encodeUtf8 k, "=",
                                     "'", v, "'"]
-          formOptions = B.intercalate " " $ map formFn $ Map.toList formData
+          formOptions = B.intercalate " " $ map formFn $ H.toList formData
 
 
         return $ B.intercalate " " $
diff --git a/examples/PresignedPostPolicy.hs b/examples/PresignedPostPolicy.hs
index c079eca..825118a 100755
--- a/examples/PresignedPostPolicy.hs
+++ b/examples/PresignedPostPolicy.hs
@@ -22,7 +22,7 @@ import           Network.Minio
 
 import qualified Data.ByteString       as B
 import qualified Data.ByteString.Char8 as Char8
-import qualified Data.Map.Strict       as Map
+import qualified Data.HashMap.Strict   as H
 import qualified Data.Text.Encoding    as Enc
 import qualified Data.Time             as Time
 
@@ -69,7 +69,7 @@ main = do
         let
           formFn (k, v) = B.concat ["-F ", Enc.encodeUtf8 k, "=",
                                     "'", v, "'"]
-          formOptions = B.intercalate " " $ map formFn $ Map.toList formData
+          formOptions = B.intercalate " " $ map formFn $ H.toList formData
 
 
         return $ B.intercalate " " $
diff --git a/minio-hs.cabal b/minio-hs.cabal
index 8a081f8..74793cb 100644
--- a/minio-hs.cabal
+++ b/minio-hs.cabal
@@ -1,5 +1,5 @@
 name:                minio-hs
-version:             1.4.0
+version:             1.5.0
 synopsis:            A MinIO Haskell Library for Amazon S3 compatible cloud
                      storage.
 description:         The MinIO Haskell client library provides simple APIs to
@@ -57,7 +57,6 @@ library
                      , conduit >= 1.3
                      , conduit-extra >= 1.3
                      , connection
-                     , containers >= 0.5
                      , cryptonite >= 0.25
                      , cryptonite-conduit >= 0.2
                      , digest >= 0.0.1
@@ -153,7 +152,6 @@ test-suite minio-hs-live-server-test
                      , conduit
                      , conduit-extra
                      , connection
-                     , containers
                      , cryptonite
                      , cryptonite-conduit
                      , digest
@@ -200,7 +198,6 @@ test-suite minio-hs-test
                      , conduit
                      , conduit-extra
                      , connection
-                     , containers
                      , cryptonite
                      , cryptonite-conduit
                      , digest
diff --git a/src/Network/Minio/API.hs b/src/Network/Minio/API.hs
index 3d29354..7359bca 100644
--- a/src/Network/Minio/API.hs
+++ b/src/Network/Minio/API.hs
@@ -34,7 +34,7 @@ import           Control.Retry             (fullJitterBackoff,
 import qualified Data.ByteString           as B
 import qualified Data.Char                 as C
 import qualified Data.Conduit              as C
-import qualified Data.Map                  as Map
+import qualified Data.HashMap.Strict       as H
 import qualified Data.Text                 as T
 import qualified Data.Time.Clock           as Time
 import           Network.HTTP.Conduit      (Response)
@@ -95,7 +95,7 @@ getRegionHost r = do
 
     if "amazonaws.com" `T.isSuffixOf` connectHost ci
     then maybe (throwIO $ MErrVRegionNotSupported r)
-         return (Map.lookup r awsRegionMap)
+         return (H.lookup r awsRegionMap)
     else return $ connectHost ci
 
 buildRequest :: S3ReqInfo -> Minio NC.Request
diff --git a/src/Network/Minio/Data.hs b/src/Network/Minio/Data.hs
index 6f89f55..2bd10f1 100644
--- a/src/Network/Minio/Data.hs
+++ b/src/Network/Minio/Data.hs
@@ -32,7 +32,6 @@ import qualified Data.ByteString              as B
 import           Data.CaseInsensitive         (mk)
 import qualified Data.HashMap.Strict          as H
 import qualified Data.Ini                     as Ini
-import qualified Data.Map                     as Map
 import           Data.String                  (IsString (..))
 import qualified Data.Text                    as T
 import qualified Data.Text.Encoding           as TE
@@ -74,8 +73,8 @@ maxMultipartParts = 10000
 -- type should have a IsString instance to infer the appropriate
 -- constant.
 -- | awsRegionMap - library constant
-awsRegionMap :: Map.Map Text Text
-awsRegionMap = Map.fromList [
+awsRegionMap :: H.HashMap Text Text
+awsRegionMap = H.fromList [
       ("us-east-1", "s3.amazonaws.com")
     , ("us-east-2", "s3-us-east-2.amazonaws.com")
     , ("us-west-1", "s3-us-west-1.amazonaws.com")
@@ -440,8 +439,8 @@ data ObjectInfo = ObjectInfo
   , oiModTime  :: UTCTime -- ^ Mdification time of the object
   , oiETag     :: ETag -- ^ ETag of the object
   , oiSize     :: Int64 -- ^ Size of the object in bytes
-  , oiMetadata :: Map.Map Text Text -- ^ A map of the metadata
-                                    -- key-value pairs
+  , oiMetadata :: H.HashMap Text Text -- ^ A map of the metadata
+                                      -- key-value pairs
   } deriving (Show, Eq)
 
 -- | Represents source object in server-side copy object
@@ -928,7 +927,7 @@ getS3Path b o =
 -- seconds. The maximum duration that can be specified is 7 days.
 type UrlExpiry = Int
 
-type RegionMap = Map.Map Bucket Region
+type RegionMap = H.HashMap Bucket Region
 
 -- | The Minio Monad - all computations accessing object storage
 -- happens in it.
@@ -991,7 +990,7 @@ runMinioWith conn m = runResourceT $ runMinioResWith conn m
 -- `MinioConn`.
 mkMinioConn :: ConnectInfo -> NC.Manager -> IO MinioConn
 mkMinioConn ci mgr = do
-    rMapMVar <- M.newMVar Map.empty
+    rMapMVar <- M.newMVar H.empty
     return $ MinioConn ci mgr rMapMVar
 
 -- | Run the Minio action and return the result or an error.
diff --git a/src/Network/Minio/PresignedOperations.hs b/src/Network/Minio/PresignedOperations.hs
index ab289c4..d929e7e 100644
--- a/src/Network/Minio/PresignedOperations.hs
+++ b/src/Network/Minio/PresignedOperations.hs
@@ -39,7 +39,7 @@ module Network.Minio.PresignedOperations
 import           Data.Aeson                ((.=))
 import qualified Data.Aeson                as Json
 import           Data.ByteString.Builder   (byteString, toLazyByteString)
-import qualified Data.Map.Strict           as Map
+import qualified Data.HashMap.Strict       as H
 import qualified Data.Text                 as T
 import qualified Data.Time                 as Time
 import qualified Network.HTTP.Conduit      as NC
@@ -252,7 +252,7 @@ showPostPolicy = toS . Json.encode
 -- browser. On success, this function returns a URL and POST
 -- form-data.
 presignedPostPolicy :: PostPolicy
-                    -> Minio (ByteString, Map.Map Text ByteString)
+                    -> Minio (ByteString, H.HashMap Text ByteString)
 presignedPostPolicy p = do
   ci <- asks mcConnInfo
   signTime <- liftIO $ Time.getCurrentTime
@@ -277,12 +277,12 @@ presignedPostPolicy p = do
     mkPair (PPCStartsWith k v) = Just (k, v)
     mkPair (PPCEquals k v)     = Just (k, v)
     mkPair _                   = Nothing
-    formFromPolicy = Map.map toS $ Map.fromList $ catMaybes $
+    formFromPolicy = H.map toS $ H.fromList $ catMaybes $
                      mkPair <$> conditions ppWithCreds
-    formData = formFromPolicy `Map.union` signData
+    formData = formFromPolicy `H.union` signData
 
     -- compute POST upload URL
-    bucket = Map.findWithDefault "" "bucket" formData
+    bucket = H.lookupDefault "" "bucket" formData
     scheme = byteString $ bool "http://" "https://" $ connectIsSecure ci
     region = connectRegion ci
 
diff --git a/src/Network/Minio/Sign/V4.hs b/src/Network/Minio/Sign/V4.hs
index 57f6824..d5836e2 100644
--- a/src/Network/Minio/Sign/V4.hs
+++ b/src/Network/Minio/Sign/V4.hs
@@ -22,8 +22,8 @@ import qualified Data.ByteString.Base64        as Base64
 import qualified Data.ByteString.Char8         as B8
 import           Data.CaseInsensitive          (mk)
 import qualified Data.CaseInsensitive          as CI
-import qualified Data.Map.Strict               as Map
-import qualified Data.Set                      as Set
+import qualified Data.HashMap.Strict           as Map
+import qualified Data.HashSet                  as Set
 import qualified Data.Time                     as Time
 import qualified Network.HTTP.Conduit          as NC
 import           Network.HTTP.Types            (Header, parseQuery)
@@ -39,7 +39,7 @@ import           Network.Minio.Errors
 
 -- these headers are not included in the string to sign when signing a
 -- request
-ignoredHeaders :: Set ByteString
+ignoredHeaders :: Set.HashSet ByteString
 ignoredHeaders = Set.fromList $ map CI.foldedCase
                  [ H.hAuthorization
                  , H.hContentType
@@ -178,7 +178,7 @@ mkScope ts region = B.intercalate "/"
 
 getHeadersToSign :: [Header] -> [(ByteString, ByteString)]
 getHeadersToSign !h =
-  filter (flip Set.notMember ignoredHeaders . fst) $
+  filter ((\hdr -> not $ Set.member hdr ignoredHeaders) . fst) $
   map (\(x, y) -> (CI.foldedCase x, stripBS y)) h
 
 mkCanonicalRequest :: Bool -> SignParams -> NC.Request -> [(ByteString, ByteString)]
@@ -234,7 +234,7 @@ computeSignature !toSign !key = digestToBase16 $ hmacSHA256 toSign key
 -- and ConnInfo and returns form-data for the POST upload containing
 -- just the signature and the encoded post-policy.
 signV4PostPolicy :: ByteString -> SignParams
-                 -> Map.Map Text ByteString
+                 -> Map.HashMap Text ByteString
 signV4PostPolicy !postPolicyJSON !sp =
   let
     stringToSign = Base64.encode postPolicyJSON
diff --git a/src/Network/Minio/Utils.hs b/src/Network/Minio/Utils.hs
index 8f2d67d..9b17f9b 100644
--- a/src/Network/Minio/Utils.hs
+++ b/src/Network/Minio/Utils.hs
@@ -23,8 +23,8 @@ import qualified Data.ByteString               as B
 import qualified Data.ByteString.Lazy          as LB
 import           Data.CaseInsensitive          (mk, original)
 import qualified Data.Conduit.Binary           as CB
+import qualified Data.HashMap.Strict           as H
 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)
@@ -105,8 +105,8 @@ getETagHeader hs = decodeUtf8Lenient <$> lookupHeader Hdr.hETag hs
 getMetadata :: [HT.Header] -> [(Text, Text)]
 getMetadata = map ((\(x, y) -> (decodeUtf8Lenient $ original x, decodeUtf8Lenient $ stripBS y)))
 
-getMetadataMap :: [HT.Header] -> Map Text Text
-getMetadataMap hs = Map.fromList (getMetadata hs)
+getMetadataMap :: [HT.Header] -> H.HashMap Text Text
+getMetadataMap hs = H.fromList (getMetadata hs)
 
 getLastModifiedHeader :: [HT.Header] -> Maybe UTCTime
 getLastModifiedHeader hs = do
@@ -245,14 +245,14 @@ lookupRegionCache :: Bucket -> Minio (Maybe Region)
 lookupRegionCache b = do
     rMVar <- asks mcRegionMap
     rMap <- UM.readMVar rMVar
-    return $ Map.lookup b rMap
+    return $ H.lookup b rMap
 
 addToRegionCache :: Bucket -> Region -> Minio ()
 addToRegionCache b region = do
     rMVar <- asks mcRegionMap
-    UM.modifyMVar_ rMVar $ return . Map.insert b region
+    UM.modifyMVar_ rMVar $ return . H.insert b region
 
 deleteFromRegionCache :: Bucket -> Minio ()
 deleteFromRegionCache b = do
     rMVar <- asks mcRegionMap
-    UM.modifyMVar_ rMVar $ return . Map.delete b
+    UM.modifyMVar_ rMVar $ return . H.delete b
diff --git a/src/Network/Minio/XmlParser.hs b/src/Network/Minio/XmlParser.hs
index 561a8bf..6217fba 100644
--- a/src/Network/Minio/XmlParser.hs
+++ b/src/Network/Minio/XmlParser.hs
@@ -30,8 +30,8 @@ module Network.Minio.XmlParser
   ) where
 
 import qualified Data.ByteString.Lazy as LB
+import qualified Data.HashMap.Strict  as H
 import           Data.List            (zip3, zip4, zip5)
-import qualified Data.Map             as Map
 import qualified Data.Text            as T
 import           Data.Text.Read       (decimal)
 import           Data.Time
@@ -149,7 +149,7 @@ parseListObjectsV1Response xmldata = do
   sizes <- parseDecimals sizeStr
 
   let
-    objects = map (uncurry5 ObjectInfo) $ zip5 keys modTimes etags sizes (repeat Map.empty)
+    objects = map (uncurry5 ObjectInfo) $ zip5 keys modTimes etags sizes (repeat H.empty)
 
   return $ ListObjectsV1Result hasMore nextMarker objects prefixes
 
@@ -178,7 +178,7 @@ parseListObjectsResponse xmldata = do
   sizes <- parseDecimals sizeStr
 
   let
-    objects = map (uncurry5 ObjectInfo) $ zip5 keys modTimes etags sizes (repeat Map.empty)
+    objects = map (uncurry5 ObjectInfo) $ zip5 keys modTimes etags sizes (repeat H.empty)
 
   return $ ListObjectsResult hasMore nextToken objects prefixes
 
diff --git a/test/LiveServer.hs b/test/LiveServer.hs
index ea5f40a..180bfe8 100644
--- a/test/LiveServer.hs
+++ b/test/LiveServer.hs
@@ -27,7 +27,7 @@ import           Data.Conduit                          (yield)
 import qualified Data.Conduit                          as C
 import qualified Data.Conduit.Binary                   as CB
 import           Data.Conduit.Combinators              (sinkList)
-import qualified Data.Map.Strict                       as Map
+import qualified Data.HashMap.Strict                   as H
 import qualified Data.Text                             as T
 import           Data.Time                             (fromGregorian)
 import qualified Data.Time                             as Time
@@ -513,8 +513,8 @@ presignedUrlFunTest = funTestWithBucket "presigned Url tests" $
       "presigned HEAD failed (presignedHeadObjectUrl)"
 
     -- check that header info is accurate
-    let h = Map.fromList $ NC.responseHeaders headResp
-        cLen = Map.findWithDefault "0" HT.hContentLength h
+    let h = H.fromList $ NC.responseHeaders headResp
+        cLen = H.lookupDefault "0" HT.hContentLength h
     liftIO $ (cLen == show size2) @? "Head req returned bad content length"
 
     step "GET object presigned URL - presignedGetObjectUrl"
@@ -580,7 +580,7 @@ presignedPostPolicyFunTest = funTestWithBucket "Presigned Post Policy tests" $
       postForm url formData inputFile = do
         req <- NC.parseRequest $ toS url
         let parts = map (\(x, y) -> Form.partBS x y) $
-                    Map.toList formData
+                    H.toList formData
             parts' = parts ++ [Form.partFile "file" inputFile]
         req' <- Form.formDataBody parts' req
         mgr <- NC.newManager NC.tlsManagerSettings
@@ -698,7 +698,7 @@ putObjectContentTypeTest = funTestWithBucket "putObject contentType tests" $
     let m = oiMetadata oi
 
     step "Validate content-type"
-    liftIO $ assertEqual "Content-Type did not match" (Just "application/javascript") (Map.lookup "Content-Type" m)
+    liftIO $ assertEqual "Content-Type did not match" (Just "application/javascript") (H.lookup "Content-Type" m)
 
     step "upload object with content-encoding set to identity"
     fPutObject bucket object inputFile defaultPutObjectOptions {
@@ -710,7 +710,7 @@ putObjectContentTypeTest = funTestWithBucket "putObject contentType tests" $
 
     step "Validate content-encoding"
     liftIO $ assertEqual "Content-Encoding did not match" (Just "identity")
-      (Map.lookup "Content-Encoding" m')
+      (H.lookup "Content-Encoding" m')
 
     step "Cleanup actions"
 
@@ -735,7 +735,7 @@ putObjectContentLanguageTest = funTestWithBucket "putObject contentLanguage test
 
     step "Validate content-language"
     liftIO $ assertEqual "content-language did not match" (Just "en-US")
-      (Map.lookup "Content-Language" m)
+      (H.lookup "Content-Language" m)
     step "Cleanup actions"
 
     removeObject bucket object
@@ -771,7 +771,7 @@ putObjectStorageClassTest = funTestWithBucket "putObject storageClass tests" $
 
     step "Validate x-amz-storage-class rrs"
     liftIO $ assertEqual "storageClass did not match" (Just "REDUCED_REDUNDANCY")
-      (Map.lookup "X-Amz-Storage-Class" m')
+      (H.lookup "X-Amz-Storage-Class" m')
 
     fpE <- try $ fPutObject bucket object'' inputFile'' defaultPutObjectOptions {
       pooStorageClass = Just "INVALID_STORAGE_CLASS"
diff --git a/test/Network/Minio/XmlParser/Test.hs b/test/Network/Minio/XmlParser/Test.hs
index 920a1c1..e32b28a 100644
--- a/test/Network/Minio/XmlParser/Test.hs
+++ b/test/Network/Minio/XmlParser/Test.hs
@@ -19,7 +19,7 @@ module Network.Minio.XmlParser.Test
   ( xmlParserTests
   ) where
 
-import qualified Data.Map                  as Map
+import qualified Data.HashMap.Strict       as H
 import           Data.Time                 (fromGregorian)
 import           Test.Tasty
 import           Test.Tasty.HUnit
@@ -128,7 +128,7 @@ testParseListObjectsResult = do
               \</ListBucketResult>"
 
     expectedListResult = ListObjectsResult True (Just "opaque") [object1] []
-    object1 = ObjectInfo "my-image.jpg" modifiedTime1 "\"fba9dede5f27731c9771645a39863328\"" 434234 Map.empty
+    object1 = ObjectInfo "my-image.jpg" modifiedTime1 "\"fba9dede5f27731c9771645a39863328\"" 434234 H.empty
     modifiedTime1 = flip UTCTime 64230 $ fromGregorian 2009 10 12
 
   parsedListObjectsResult <- tryValidationErr $ runTestNS $ parseListObjectsResponse xmldata
@@ -155,7 +155,7 @@ testParseListObjectsV1Result = do
               \</ListBucketResult>"
 
     expectedListResult = ListObjectsV1Result True (Just "my-image1.jpg") [object1] []
-    object1 = ObjectInfo "my-image.jpg" modifiedTime1 "\"fba9dede5f27731c9771645a39863328\"" 434234 Map.empty
+    object1 = ObjectInfo "my-image.jpg" modifiedTime1 "\"fba9dede5f27731c9771645a39863328\"" 434234 H.empty
     modifiedTime1 = flip UTCTime 64230 $ fromGregorian 2009 10 12
 
   parsedListObjectsV1Result <- tryValidationErr $ runTestNS $ parseListObjectsV1Response xmldata