diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,7 @@
+0.3.11 [2024.12.04]
+-------------------
+* Drop support for pre-8.0 versions of GHC.
+
 0.3.10 [2023.08.06]
 -------------------
 * Allow building with `bytestring-0.12.*`.
diff --git a/charset.cabal b/charset.cabal
--- a/charset.cabal
+++ b/charset.cabal
@@ -1,5 +1,5 @@
 name:          charset
-version:       0.3.10
+version:       0.3.11
 license:       BSD3
 license-File:  LICENSE
 copyright:     (c) Edward Kmett 2010-2012
@@ -16,22 +16,19 @@
 extra-source-files: CHANGELOG.markdown, README.markdown
 
 tested-with:
-  GHC ==7.0.4
-   || ==7.2.2
-   || ==7.4.2
-   || ==7.6.3
-   || ==7.8.4
-   || ==7.10.3
-   || ==8.0.2
+  GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
    || ==8.6.5
    || ==8.8.4
    || ==8.10.7
    || ==9.0.2
-   || ==9.2.7
-   || ==9.4.5
-   || ==9.6.2
+   || ==9.2.8
+   || ==9.4.8
+   || ==9.6.6
+   || ==9.8.4
+   || ==9.10.1
+   || ==9.12.1
 
 source-repository head
   type: git
@@ -42,13 +39,11 @@
   other-extensions: MagicHash, BangPatterns
 
   build-depends:
-    base                 >= 4       && < 5,
+    base                 >= 4.9     && < 5,
     array                >= 0.2     && < 0.6,
     bytestring           >= 0.9     && < 0.13,
-    containers           >= 0.2     && < 0.7,
+    containers           >= 0.2     && < 0.8,
     unordered-containers >= 0.1.4.6 && < 0.3
-  if impl(ghc < 8.0)
-    build-depends: semigroups >= 0.8.3.1 && < 1
 
   exposed-modules:
     Data.CharSet
diff --git a/src/Data/CharSet.hs b/src/Data/CharSet.hs
--- a/src/Data/CharSet.hs
+++ b/src/Data/CharSet.hs
@@ -1,9 +1,6 @@
 {-# OPTIONS_GHC -fspec-constr #-}
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE DeriveDataTypeable #-}
-#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
 {-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.CharSet
@@ -75,11 +72,6 @@
     , toArray
     ) where
 
-#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 608
-import Data.String (IsString(..))
--- <<< -XOverloadedStrings >>> was introduced by GHC 6.8.1
-#endif
-
 import Data.Array.Unboxed hiding (range)
 import Data.Data
 import Data.Function (on)
@@ -90,6 +82,7 @@
 import Data.Word
 import Data.ByteString.Internal (c2w)
 import Data.Semigroup
+import Data.String (IsString(..))
 import qualified Data.IntSet as I
 import qualified Data.List as L
 import Prelude hiding (filter, map, null)
@@ -104,13 +97,10 @@
     !Bool    -- Whether ByteSet and IntSet are negated
     !ByteSet -- Set of head bytes, unboxed
     !IntSet  -- Set of characters in the charset
-  deriving Typeable
 
-#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 608
 -- | @= CharSet.`fromList`@
 instance IsString CharSet where
   fromString = fromList
-#endif
 
 charSet :: Bool -> IntSet -> CharSet
 charSet b s = CharSet b (ByteSet.fromList (fmap headByte (I.toAscList s))) s
diff --git a/src/Data/CharSet/ByteSet.hs b/src/Data/CharSet/ByteSet.hs
--- a/src/Data/CharSet/ByteSet.hs
+++ b/src/Data/CharSet/ByteSet.hs
@@ -1,8 +1,6 @@
 {-# LANGUAGE BangPatterns, MagicHash #-}
 {-# LANGUAGE CPP #-}
-#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
 {-# LANGUAGE Trustworthy #-}
-#endif
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.CharSet.ByteSet
@@ -32,6 +30,7 @@
 
 import Data.Bits ((.&.), (.|.))
 import Foreign.Storable (peekByteOff, pokeByteOff)
+import Foreign.Marshal.Utils (fillBytes)
 import GHC.Exts ( Int(I#), Word#, iShiftRA#, shiftL#
 #if MIN_VERSION_base(4,16,0)
                 , Word8#, word8ToWord#, wordToWord8#
@@ -44,10 +43,6 @@
 import qualified Data.ByteString.Internal as I
 import qualified Data.ByteString.Unsafe as U
 
-#if MIN_VERSION_base(4,8,0)
-import Foreign.Marshal.Utils (fillBytes)
-#endif
-
 newtype ByteSet = ByteSet B.ByteString deriving (Eq, Ord, Show)
 
 -- | Representation of the index of a bit inside a bytestring
@@ -69,12 +64,7 @@
 
 fromList :: [Word8] -> ByteSet
 fromList s0 = ByteSet $ I.unsafeCreate 32 $ \t -> do
-  _ <-
-#if MIN_VERSION_base(4,8,0)
-    fillBytes t 0 32
-#else
-    I.memset t 0 32
-#endif
+  _ <- fillBytes t 0 32
   let go [] = return ()
       go (c:cs) = do
         prev <- peekByteOff t byte :: IO Word8
diff --git a/src/Data/CharSet/Unicode.hs b/src/Data/CharSet/Unicode.hs
--- a/src/Data/CharSet/Unicode.hs
+++ b/src/Data/CharSet/Unicode.hs
@@ -44,7 +44,7 @@
 import Data.CharSet
 
 data UnicodeCategory = UnicodeCategory String String CharSet String
-    deriving (Show, Data, Typeable)
+    deriving (Show, Data)
 
 -- \p{Letter} or \p{Mc}
 unicodeCategories :: [UnicodeCategory]
diff --git a/src/Data/CharSet/Unicode/Block.hs b/src/Data/CharSet/Unicode/Block.hs
--- a/src/Data/CharSet/Unicode/Block.hs
+++ b/src/Data/CharSet/Unicode/Block.hs
@@ -1,5 +1,5 @@
 {-# LANGUAGE DeriveDataTypeable #-}
-{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
+{-# OPTIONS_GHC -Wno-missing-signatures #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.CharSet.Unicode.Block
@@ -139,7 +139,7 @@
 data Block = Block
     { blockName :: String
     , blockCharSet :: CharSet
-    } deriving (Show, Data, Typeable)
+    } deriving (Show, Data)
 
 blocks :: [Block]
 blocks =
diff --git a/src/Data/CharSet/Unicode/Category.hs b/src/Data/CharSet/Unicode/Category.hs
--- a/src/Data/CharSet/Unicode/Category.hs
+++ b/src/Data/CharSet/Unicode/Category.hs
@@ -55,7 +55,7 @@
     , categoryAbbreviation :: String
     , categoryCharSet :: CharSet
     , categoryDescription :: String
-    } deriving (Show, Data, Typeable)
+    } deriving (Show, Data)
 
 -- \p{Letter} or \p{Mc}
 categories :: [Category]