diff --git a/src/Yam/Middleware.hs b/src/Yam/Middleware.hs
--- a/src/Yam/Middleware.hs
+++ b/src/Yam/Middleware.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP            #-}
 {-# LANGUAGE ImplicitParams #-}
 module Yam.Middleware(
     AppMiddleware(..)
@@ -12,11 +13,17 @@
 -- | Application Middleware
 newtype AppMiddleware = AppMiddleware {runAM :: Env -> ((Env, Middleware)-> LoggingT IO ()) -> LoggingT IO ()}
 
-instance Semigroup AppMiddleware where
-  (AppMiddleware am) <> (AppMiddleware bm) = AppMiddleware $ \e f -> am e $ \(e', mw) -> bm e' $ \(e'',mw') -> f (e'', mw . mw')
-
 instance Monoid AppMiddleware where
   mempty = AppMiddleware $ \a f -> f (a,id)
+#if __GLASGOW_HASKELL__ >= 804
+instance Semigroup AppMiddleware where
+  (<>) = _append
+#else
+  mappend = _append
+#endif
+
+
+_append (AppMiddleware am) (AppMiddleware bm) = AppMiddleware $ \e f -> am e $ \(e', mw) -> bm e' $ \(e'',mw') -> f (e'', mw . mw')
 
 -- | Simple AppMiddleware
 simpleAppMiddleware :: HasCallStack => (Bool, Text) -> Key a -> a -> AppMiddleware
diff --git a/src/Yam/Types/Prelude.hs b/src/Yam/Types/Prelude.hs
--- a/src/Yam/Types/Prelude.hs
+++ b/src/Yam/Types/Prelude.hs
@@ -10,12 +10,6 @@
   , randomCode
   , whenException
   -- * Reexport Functions
-#if !MIN_VERSION_salak(0,1,7)
-  , (.>>)
-  , (.?>)
-  , (.?=)
-  , (.|=)
-#endif
   , LogFunc
   , Default(..)
   , Text
@@ -29,6 +23,7 @@
   , throw
   , try
   , catch
+  , (<>)
   , module Data.Proxy
   , module Data.Vault.Lazy
   , module Data.Maybe
@@ -59,6 +54,7 @@
 import           Data.Default
 import           Data.Function
 import           Data.Maybe
+import           Data.Monoid                        ((<>))
 import           Data.Proxy
 import           Data.Salak
     ( FromProperties (..)
@@ -67,6 +63,7 @@
     , Return
     , defaultPropertiesWithFile
     )
+import           Data.Salak                         ((.>>), (.?=), (.?>), (.|=))
 import           Data.Text                          (Text, pack)
 import           Data.Text.Encoding                 (decodeUtf8, encodeUtf8)
 import           Data.Vault.Lazy                    (Key, Vault, newKey)
@@ -80,37 +77,6 @@
 import           Servant.Server.Internal.ServantErr
 import           System.IO.Unsafe                   (unsafePerformIO)
 import           System.Random.MWC
-
-#if MIN_VERSION_salak(0,1,7)
-import           Data.Salak                         ((.>>), (.?=), (.?>), (.|=))
-#else
-import qualified Data.Salak                         as S
-import           Data.Text                          (unpack)
-
-infixl 5 .?>
-(.?>) :: FromProperties a => Properties -> Text -> Return a
-(.?>) = flip S.lookup'
-
-infixl 5 .|=
-(.|=) :: Return a -> a -> a
-(.|=) (S.OK   a) _ = a
-(.|=) (S.Fail e) _ = error e
-(.|=) _        d   = d
-
-infixl 5 .?=
-(.?=) :: Return a -> a -> Return a
-(.?=) a b = S.OK (a .|= b)
-
-infixl 5 .>>
-(.>>) :: FromProperties a => Properties -> Text -> a
-(.>>) p k = case p .?> k of
-  S.OK v   -> v
-  S.Empty  -> case fromProperties S.empty of
-    (S.OK   a) -> a
-    (S.Fail e) -> error e
-    _          -> error $ "Config " <> unpack k <> " not found"
-  S.Fail e -> error e
-#endif
 
 type LogFunc = Loc -> LogSource -> LogLevel -> LogStr -> IO ()
 
diff --git a/yam.cabal b/yam.cabal
--- a/yam.cabal
+++ b/yam.cabal
@@ -1,6 +1,6 @@
 cabal-version: 1.12
 name: yam
-version: 0.5.10
+version: 0.5.11
 license: BSD3
 license-file: LICENSE
 copyright: (c) 2018 Daniel YU
@@ -47,11 +47,9 @@
                         RecordWildCards ScopedTypeVariables StandaloneDeriving
                         TupleSections TypeApplications TypeFamilies TypeOperators
                         TypeSynonymInstances ViewPatterns
-    ghc-options: -Wall -Wcompat -Wincomplete-record-updates
-                 -Wincomplete-uni-patterns -Wredundant-constraints -fno-warn-orphans
-                 -fno-warn-missing-signatures
+    ghc-options: -Wall -fno-warn-orphans -fno-warn-missing-signatures
     build-depends:
-        base >=4.11 && <5,
+        base >=4.9 && <5,
         base16-bytestring >=0.1.1.6 && <0.2,
         binary >=0.8.6.0 && <0.9,
         bytestring >=0.10.8.2 && <0.11,
@@ -114,12 +112,10 @@
                         RecordWildCards ScopedTypeVariables StandaloneDeriving
                         TupleSections TypeApplications TypeFamilies TypeOperators
                         TypeSynonymInstances ViewPatterns
-    ghc-options: -Wall -Wcompat -Wincomplete-record-updates
-                 -Wincomplete-uni-patterns -Wredundant-constraints -fno-warn-orphans
-                 -fno-warn-missing-signatures
+    ghc-options: -Wall -fno-warn-orphans -fno-warn-missing-signatures
     build-depends:
         QuickCheck >=2.12.6.1 && <2.13,
-        base >=4.11 && <5,
+        base >=4.9 && <5,
         base16-bytestring >=0.1.1.6 && <0.2,
         binary >=0.8.6.0 && <0.9,
         bytestring >=0.10.8.2 && <0.11,