diff --git a/hackage-repo-tool/src/Hackage/Security/RepoTool/Util/IO.hs b/hackage-repo-tool/src/Hackage/Security/RepoTool/Util/IO.hs
index b6cd0312..bfb50927 100644
--- a/hackage-repo-tool/src/Hackage/Security/RepoTool/Util/IO.hs
+++ b/hackage-repo-tool/src/Hackage/Security/RepoTool/Util/IO.hs
@@ -123,11 +123,6 @@ data TarGzError = TarGzError FilePath SomeException
   deriving (Typeable)
 
 instance Exception TarGzError where
-#if MIN_VERSION_base(4,8,0)
   displayException (TarGzError path e) = path ++ ": " ++ displayException e
 
 deriving instance Show TarGzError
-#else
-instance Show TarGzError where
-  show (TarGzError path e) = path ++ ": " ++ show e
-#endif
diff --git a/hackage-repo-tool/src/Main.hs b/hackage-repo-tool/src/Main.hs
index 3615c6f8..e871b4de 100644
--- a/hackage-repo-tool/src/Main.hs
+++ b/hackage-repo-tool/src/Main.hs
@@ -77,11 +77,6 @@ topLevelExceptionHandler e = do
     putStrLn $ displayException e
     exitFailure
 
-#if !MIN_VERSION_base(4,8,0)
-displayException :: Exception e => e -> String
-displayException = show
-#endif
-
 {-------------------------------------------------------------------------------
   Creating keys
 -------------------------------------------------------------------------------}
diff --git a/hackage-root-tool/Main.hs b/hackage-root-tool/Main.hs
index 7dff1fc2..da80d596 100644
--- a/hackage-root-tool/Main.hs
+++ b/hackage-root-tool/Main.hs
@@ -49,11 +49,6 @@ topLevelExceptionHandler e = do
     putStrLn $ displayException e
     exitFailure
 
-#if !MIN_VERSION_base(4,8,0)
-displayException :: Exception e => e -> String
-displayException = show
-#endif
-
 {-------------------------------------------------------------------------------
   Creating keys
 -------------------------------------------------------------------------------}
diff --git a/hackage-security-HTTP/src/Hackage/Security/Client/Repository/HttpLib/HTTP.hs b/hackage-security-HTTP/src/Hackage/Security/Client/Repository/HttpLib/HTTP.hs
index e17d3fcb..dd3ca6f7 100644
--- a/hackage-security-HTTP/src/Hackage/Security/Client/Repository/HttpLib/HTTP.hs
+++ b/hackage-security-HTTP/src/Hackage/Security/Client/Repository/HttpLib/HTTP.hs
@@ -133,17 +133,10 @@ instance Pretty UnexpectedResponse where
 instance Pretty InvalidProxy where
   pretty (InvalidProxy p) = "Invalid proxy " ++ show p
 
-#if MIN_VERSION_base(4,8,0)
 deriving instance Show UnexpectedResponse
 deriving instance Show InvalidProxy
 instance Exception UnexpectedResponse where displayException = pretty
 instance Exception InvalidProxy where displayException = pretty
-#else
-instance Show UnexpectedResponse where show = pretty
-instance Show InvalidProxy where show = pretty
-instance Exception UnexpectedResponse
-instance Exception InvalidProxy
-#endif
 
 {-------------------------------------------------------------------------------
   Additional operations
diff --git a/hackage-security/src/Hackage/Security/Client.hs b/hackage-security/src/Hackage/Security/Client.hs
index 5ccf46cb..c85b21f3 100644
--- a/hackage-security/src/Hackage/Security/Client.hs
+++ b/hackage-security/src/Hackage/Security/Client.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 710
 {-# LANGUAGE StaticPointers #-}
-#endif
+
 -- | Main entry point into the Hackage Security framework for clients
 module Hackage.Security.Client (
     -- * Checking for updates
@@ -952,21 +951,12 @@ data InvalidFileInIndex = forall dec. InvalidFileInIndex {
   }
   deriving (Typeable)
 
-#if MIN_VERSION_base(4,8,0)
 deriving instance Show InvalidPackageException
 deriving instance Show LocalFileCorrupted
 deriving instance Show InvalidFileInIndex
 instance Exception InvalidPackageException where displayException = pretty
 instance Exception LocalFileCorrupted where displayException = pretty
 instance Exception InvalidFileInIndex where displayException = pretty
-#else
-instance Show InvalidPackageException where show = pretty
-instance Show LocalFileCorrupted where show = pretty
-instance Show InvalidFileInIndex where show = pretty
-instance Exception InvalidPackageException
-instance Exception LocalFileCorrupted
-instance Exception InvalidFileInIndex
-#endif
 
 instance Pretty InvalidPackageException where
   pretty (InvalidPackageException pkgId) = "Invalid package " ++ display pkgId
diff --git a/hackage-security/src/Hackage/Security/Client/Repository.hs b/hackage-security/src/Hackage/Security/Client/Repository.hs
index 395c2458..93dd76b0 100644
--- a/hackage-security/src/Hackage/Security/Client/Repository.hs
+++ b/hackage-security/src/Hackage/Security/Client/Repository.hs
@@ -385,13 +385,8 @@ data SomeRemoteError :: * where
     SomeRemoteError :: Exception e => e -> SomeRemoteError
   deriving (Typeable)
 
-#if MIN_VERSION_base(4,8,0)
 deriving instance Show SomeRemoteError
 instance Exception SomeRemoteError where displayException = pretty
-#else
-instance Exception SomeRemoteError
-instance Show SomeRemoteError where show = pretty
-#endif
 
 instance Pretty SomeRemoteError where
     pretty (SomeRemoteError ex) = displayException ex
diff --git a/hackage-security/src/Hackage/Security/Client/Repository/Remote.hs b/hackage-security/src/Hackage/Security/Client/Repository/Remote.hs
index 9917c0c1..47640190 100644
--- a/hackage-security/src/Hackage/Security/Client/Repository/Remote.hs
+++ b/hackage-security/src/Hackage/Security/Client/Repository/Remote.hs
@@ -498,13 +498,8 @@ instance Pretty FileTooLarge where
       expected (FileSizeExact n) = "exactly " ++ show n
       expected (FileSizeBound n) = "at most " ++ show n
 
-#if MIN_VERSION_base(4,8,0)
 deriving instance Show FileTooLarge
 instance Exception FileTooLarge where displayException = pretty
-#else
-instance Exception FileTooLarge
-instance Show FileTooLarge where show = pretty
-#endif
 
 {-------------------------------------------------------------------------------
   Information about remote files
diff --git a/hackage-security/src/Hackage/Security/JSON.hs b/hackage-security/src/Hackage/Security/JSON.hs
index f9c6d29e..b4ab94c6 100644
--- a/hackage-security/src/Hackage/Security/JSON.hs
+++ b/hackage-security/src/Hackage/Security/JSON.hs
@@ -84,13 +84,8 @@ data DeserializationError =
   | DeserializationErrorFileType String String
   deriving (Typeable)
 
-#if MIN_VERSION_base(4,8,0)
 deriving instance Show DeserializationError
 instance Exception DeserializationError where displayException = pretty
-#else
-instance Show DeserializationError where show = pretty
-instance Exception DeserializationError
-#endif
 
 instance Pretty DeserializationError where
   pretty (DeserializationErrorMalformed str) =
diff --git a/hackage-security/src/Hackage/Security/Key.hs b/hackage-security/src/Hackage/Security/Key.hs
index 0c1528a0..db7cc383 100644
--- a/hackage-security/src/Hackage/Security/Key.hs
+++ b/hackage-security/src/Hackage/Security/Key.hs
@@ -37,10 +37,6 @@ import qualified Data.ByteString.Char8 as BS.C8
 import qualified Data.ByteString.Base16 as Base16
 import qualified Data.ByteString.Lazy as BS.L
 
-#if !MIN_VERSION_base(4,7,0)
-import qualified Data.Typeable as Typeable
-#endif
-
 import Hackage.Security.Util.JSON
 import Hackage.Security.Util.Some
 import Hackage.Security.Util.TypedEmbedded
@@ -277,26 +273,3 @@ instance ReportSchemaErrors m => FromJSON m (Some KeyType) where
     case tag of
       "ed25519"  -> return . Some $ KeyTypeEd25519
       _otherwise -> expected "valid key type" (Just tag)
-
-{-------------------------------------------------------------------------------
-  Orphans
-
-  Pre-7.8 (base 4.7) we cannot have Typeable instance for higher-kinded types.
-  Instead, here we provide some instance for specific instantiations.
--------------------------------------------------------------------------------}
-
-#if !MIN_VERSION_base(4,7,0)
-tyConKey, tyConPublicKey, tyConPrivateKey :: Typeable.TyCon
-tyConKey        = Typeable.mkTyCon3 "hackage-security" "Hackage.Security.Key" "Key"
-tyConPublicKey  = Typeable.mkTyCon3 "hackage-security" "Hackage.Security.Key" "PublicKey"
-tyConPrivateKey = Typeable.mkTyCon3 "hackage-security" "Hackage.Security.Key" "PrivateKey"
-
-instance Typeable (Some Key) where
-  typeOf _ = Typeable.mkTyConApp tyConSome [Typeable.mkTyConApp tyConKey []]
-
-instance Typeable (Some PublicKey) where
-  typeOf _ = Typeable.mkTyConApp tyConSome [Typeable.mkTyConApp tyConPublicKey []]
-
-instance Typeable (Some PrivateKey) where
-  typeOf _ = Typeable.mkTyConApp tyConSome [Typeable.mkTyConApp tyConPrivateKey []]
-#endif
diff --git a/hackage-security/src/Hackage/Security/Trusted.hs b/hackage-security/src/Hackage/Security/Trusted.hs
index 3b2060dc..5931d992 100644
--- a/hackage-security/src/Hackage/Security/Trusted.hs
+++ b/hackage-security/src/Hackage/Security/Trusted.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ >= 710
 {-# LANGUAGE StaticPointers #-}
-#endif
+
 module Hackage.Security.Trusted (
     module Hackage.Security.Trusted.TCB
     -- * Derived functions
diff --git a/hackage-security/src/Hackage/Security/Trusted/TCB.hs b/hackage-security/src/Hackage/Security/Trusted/TCB.hs
index 2629ac82..eecd7712 100644
--- a/hackage-security/src/Hackage/Security/Trusted/TCB.hs
+++ b/hackage-security/src/Hackage/Security/Trusted/TCB.hs
@@ -16,14 +16,8 @@ module Hackage.Security.Trusted.TCB (
   , signaturesVerified
   , verifyRole'
   , verifyFingerprints
-#if __GLASGOW_HASKELL__ >= 710
     -- * Re-exports
   , StaticPtr
-#else
-    -- * Fake static pointers
-  , StaticPtr
-  , static
-#endif
   ) where
 
 import Prelude
@@ -38,17 +32,7 @@ import Hackage.Security.Key
 import Hackage.Security.Util.Pretty
 import qualified Hackage.Security.Util.Lens as Lens
 
-#if __GLASGOW_HASKELL__ >= 710
 import GHC.StaticPtr
-#else
--- Fake static pointers for ghc < 7.10. This means Trusted offers no
--- additional type safety, but that's okay: we can still verify the code
--- with ghc 7.10 and get the additional checks.
-newtype StaticPtr a = StaticPtr { deRefStaticPtr :: a }
-
-static :: a -> StaticPtr a
-static = StaticPtr
-#endif
 
 -- | Trusted values
 --
@@ -209,17 +193,10 @@ data RootUpdated = RootUpdated
 
 type VerificationHistory = [Either RootUpdated VerificationError]
 
-#if MIN_VERSION_base(4,8,0)
 deriving instance Show VerificationError
 deriving instance Show RootUpdated
 instance Exception VerificationError where displayException = pretty
 instance Exception RootUpdated where displayException = pretty
-#else
-instance Exception VerificationError
-instance Show VerificationError where show = pretty
-instance Show RootUpdated where show = pretty
-instance Exception RootUpdated
-#endif
 
 indentedLines :: [String] -> String
 indentedLines = unlines . map ("  " ++)
diff --git a/hackage-security/src/Hackage/Security/Util/Checked.hs b/hackage-security/src/Hackage/Security/Util/Checked.hs
index b8c14d7b..006bfc5a 100644
--- a/hackage-security/src/Hackage/Security/Util/Checked.hs
+++ b/hackage-security/src/Hackage/Security/Util/Checked.hs
@@ -1,16 +1,13 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE DeriveDataTypeable  #-}
+{-# LANGUAGE IncoherentInstances #-}
+{-# LANGUAGE RoleAnnotations     #-}
+
 {-# OPTIONS_GHC -fno-warn-unused-binds #-}
 #if __GLASGOW_HASKELL__ >= 800
 {-# OPTIONS_GHC -Wno-redundant-constraints #-}
 #endif
 
-#if __GLASGOW_HASKELL__ >= 708
-{-# LANGUAGE RoleAnnotations     #-}
-{-# LANGUAGE IncoherentInstances #-}
-#endif
-
-{-# LANGUAGE DeriveDataTypeable#-}
-
 -- | Checked exceptions
 module Hackage.Security.Util.Checked (
     Throws
@@ -30,11 +27,7 @@ import Control.Exception (Exception, IOException)
 import qualified Control.Exception as Base
 import Data.Typeable (Typeable)
 
-#if __GLASGOW_HASKELL__ >= 708
 import GHC.Prim (coerce)
-#else
-import Unsafe.Coerce (unsafeCoerce)
-#endif
 
 {-------------------------------------------------------------------------------
   Basic infrastructure
@@ -43,9 +36,7 @@ import Unsafe.Coerce (unsafeCoerce)
 -- | Checked exceptions
 class Throws e where
 
-#if __GLASGOW_HASKELL__ >= 708
 type role Throws representational
-#endif
 
 unthrow :: forall a e proxy . proxy e -> (Throws e => a) -> a
 unthrow _ x = unWrap (coerceWrap (Wrap x :: Wrap e a))
@@ -56,22 +47,10 @@ unthrow _ x = unWrap (coerceWrap (Wrap x :: Wrap e a))
 
 -- | Determine if an exception is asynchronous, based on its type.
 isAsync :: Exception e => e -> Bool
-#if MIN_VERSION_base(4, 7, 0)
 isAsync e =
   case Base.fromException $ Base.toException e of
     Just Base.SomeAsyncException{} -> True
     Nothing -> False
-#else
--- Earlier versions of GHC had no SomeAsyncException. We have to
--- instead make up a list of async exceptions.
-isAsync e =
-  let se = Base.toException e
-   in case () of
-        ()
-          | Just (_ :: Base.AsyncException) <- Base.fromException se -> True
-          | show e == "<<timeout>>" -> True
-          | otherwise -> False
-#endif
 
 -- | 'Base.catch', but immediately rethrows asynchronous exceptions
 -- (as determined by 'isAsync').
@@ -131,11 +110,7 @@ internalError = throwUnchecked . userError
 newtype Wrap e a = Wrap { unWrap :: Throws e => a }
 
 coerceWrap :: Wrap e a -> Wrap (Catch e) a
-#if __GLASGOW_HASKELL__ >= 708
 coerceWrap = coerce
-#else
-coerceWrap = unsafeCoerce
-#endif
 
 data Proxy a = Proxy
 
diff --git a/hackage-security/src/Hackage/Security/Util/JSON.hs b/hackage-security/src/Hackage/Security/Util/JSON.hs
index fd8ba5b5..f35e93ca 100644
--- a/hackage-security/src/Hackage/Security/Util/JSON.hs
+++ b/hackage-security/src/Hackage/Security/Util/JSON.hs
@@ -1,7 +1,5 @@
 {-# LANGUAGE CPP #-}
-#if __GLASGOW_HASKELL__ < 710
-{-# LANGUAGE OverlappingInstances #-}
-#endif
+
 -- |
 module Hackage.Security.Util.JSON (
     -- * Type classes
@@ -120,16 +118,12 @@ instance ReportSchemaErrors m => FromJSON m Int54 where
   fromJSON val       = expected' "int" val
 
 instance
-#if __GLASGOW_HASKELL__ >= 710
   {-# OVERLAPPABLE #-}
-#endif
     (Monad m, ToJSON m a) => ToJSON m [a] where
   toJSON = liftM JSArray . mapM toJSON
 
 instance
-#if __GLASGOW_HASKELL__ >= 710
   {-# OVERLAPPABLE #-}
-#endif
     (ReportSchemaErrors m, FromJSON m a) => FromJSON m [a] where
   fromJSON (JSArray as) = mapM fromJSON as
   fromJSON val          = expected' "array" val
diff --git a/hackage-security/src/Hackage/Security/Util/Some.hs b/hackage-security/src/Hackage/Security/Util/Some.hs
index edb467fe..e36fa4f8 100644
--- a/hackage-security/src/Hackage/Security/Util/Some.hs
+++ b/hackage-security/src/Hackage/Security/Util/Some.hs
@@ -13,30 +13,17 @@ module Hackage.Security.Util.Some (
   , SomePretty(..)
     -- ** Type checking
   , typecheckSome
-#if !MIN_VERSION_base(4,7,0)
-    -- ** Compatibility with base < 4.7
-  , tyConSome
-#endif
   ) where
 
 import Prelude
-#if MIN_VERSION_base(4,7,0)
 import Data.Typeable (Typeable)
-#else
-import qualified Data.Typeable as Typeable
-#endif
 
 import Hackage.Security.Util.TypedEmbedded
 import Hackage.Security.Util.Pretty
 
 data Some f = forall a. Some (f a)
 
-#if MIN_VERSION_base(4,7,0)
 deriving instance Typeable Some
-#else
-tyConSome :: Typeable.TyCon
-tyConSome = Typeable.mkTyCon3 "hackage-security" "Hackage.Security.Util.Some" "Some"
-#endif
 
 {-------------------------------------------------------------------------------
   Equality on Some types
diff --git a/hackage-security/src/Text/JSON/Canonical.hs b/hackage-security/src/Text/JSON/Canonical.hs
index 6e7feb8d..3166bb85 100644
--- a/hackage-security/src/Text/JSON/Canonical.hs
+++ b/hackage-security/src/Text/JSON/Canonical.hs
@@ -37,14 +37,9 @@ import Text.ParserCombinators.Parsec
          , parse )
 import Text.PrettyPrint hiding (char)
 import qualified Text.PrettyPrint as Doc
-#if !(MIN_VERSION_base(4,7,0))
-import Control.Applicative ((<$>), (<$), pure, (<*>), (<*), (*>))
-#endif
 import Control.Arrow (first)
 import Data.Bits (Bits)
-#if MIN_VERSION_base(4,7,0)
 import Data.Bits (FiniteBits)
-#endif
 import Data.Char (isDigit, digitToInt)
 import Data.Data (Data)
 import Data.Function (on)
@@ -83,9 +78,7 @@ newtype Int54 = Int54 { int54ToInt64 :: Int64 }
            , Ord
            , Real
            , Ix
-#if MIN_VERSION_base(4,7,0)
            , FiniteBits
-#endif
            , Bits
            , Storable
            , PrintfArg