diff --git a/Data/Attoparsec/Text/Buffer.hs b/Data/Attoparsec/Text/Buffer.hs
--- a/Data/Attoparsec/Text/Buffer.hs
+++ b/Data/Attoparsec/Text/Buffer.hs
@@ -34,7 +34,8 @@
     , iter
     , iter_
     , substring
-    , dropWord16
+    , lengthCodeUnits
+    , dropCodeUnits
     ) where
 
 import Control.Exception (assert)
@@ -44,8 +45,14 @@
 import Data.Semigroup (Semigroup(..))
 import Data.Text ()
 import Data.Text.Internal (Text(..))
+#if MIN_VERSION_text(2,0,0)
+import Data.Text.Internal.Encoding.Utf8 (utf8LengthByLeader)
+import Data.Text.Unsafe (iterArray, lengthWord8)
+#else
 import Data.Text.Internal.Encoding.Utf16 (chr2)
 import Data.Text.Internal.Unsafe.Char (unsafeChr)
+import Data.Text.Unsafe (lengthWord16)
+#endif
 import Data.Text.Unsafe (Iter(..))
 import Foreign.Storable (sizeOf)
 import GHC.Exts (Int(..), indexIntArray#, unsafeCoerce#, writeIntArray#)
@@ -108,7 +115,11 @@
       let newgen = gen + 1
       marr <- unsafeThaw arr0
       writeGen marr newgen
+#if MIN_VERSION_text(2,0,0)
+      A.copyI newlen marr (off0+len0) arr1 off1
+#else
       A.copyI marr (off0+len0) arr1 off1 (off0+newlen)
+#endif
       arr2 <- A.unsafeFreeze marr
       return (Buf arr2 off0 newlen cap0 newgen)
     else do
@@ -116,8 +127,13 @@
           newgen = 1
       marr <- A.new (newcap + woff)
       writeGen marr newgen
+#if MIN_VERSION_text(2,0,0)
+      A.copyI len0 marr woff arr0 off0
+      A.copyI newlen marr (woff+len0) arr1 off1
+#else
       A.copyI marr woff arr0 off0 (woff+len0)
       A.copyI marr (woff+len0) arr1 off1 (woff+newlen)
+#endif
       arr2 <- A.unsafeFreeze marr
       return (Buf arr2 woff newlen newcap newgen)
 
@@ -132,12 +148,53 @@
   Text arr (off+s) l
 {-# INLINE substring #-}
 
-dropWord16 :: Int -> Buffer -> Text
-dropWord16 s (Buf arr off len _ _) =
+#if MIN_VERSION_text(2,0,0)
+
+lengthCodeUnits :: Text -> Int
+lengthCodeUnits = lengthWord8
+
+dropCodeUnits :: Int -> Buffer -> Text
+dropCodeUnits s (Buf arr off len _ _) =
   assert (s >= 0 && s <= len) $
   Text arr (off+s) (len-s)
-{-# INLINE dropWord16 #-}
+{-# INLINE dropCodeUnits #-}
 
+-- | /O(1)/ Iterate (unsafely) one step forwards through a UTF-8
+-- array, returning the current character and the delta to add to give
+-- the next offset to iterate at.
+iter :: Buffer -> Int -> Iter
+iter (Buf arr off _ _ _) i = iterArray arr (off + i)
+{-# INLINE iter #-}
+
+-- | /O(1)/ Iterate one step through a UTF-8 array, returning the
+-- delta to add to give the next offset to iterate at.
+iter_ :: Buffer -> Int -> Int
+iter_ (Buf arr off _ _ _) i = utf8LengthByLeader $ A.unsafeIndex arr (off+i)
+{-# INLINE iter_ #-}
+
+unsafeThaw :: A.Array -> ST s (A.MArray s)
+unsafeThaw (A.ByteArray a) = ST $ \s# ->
+                          (# s#, A.MutableByteArray (unsafeCoerce# a) #)
+
+readGen :: A.Array -> Int
+readGen (A.ByteArray a) = case indexIntArray# a 0# of r# -> I# r#
+
+writeGen :: A.MArray s -> Int -> ST s ()
+writeGen (A.MutableByteArray a) (I# gen#) = ST $ \s0# ->
+  case writeIntArray# a 0# gen# s0# of
+    s1# -> (# s1#, () #)
+
+#else
+
+lengthCodeUnits :: Text -> Int
+lengthCodeUnits = lengthWord16
+
+dropCodeUnits :: Int -> Buffer -> Text
+dropCodeUnits s (Buf arr off len _ _) =
+  assert (s >= 0 && s <= len) $
+  Text arr (off+s) (len-s)
+{-# INLINE dropCodeUnits #-}
+
 -- | /O(1)/ Iterate (unsafely) one step forwards through a UTF-16
 -- array, returning the current character and the delta to add to give
 -- the next offset to iterate at.
@@ -170,3 +227,5 @@
 writeGen a (I# gen#) = ST $ \s0# ->
   case writeIntArray# (A.maBA a) 0# gen# s0# of
     s1# -> (# s1#, () #)
+
+#endif
diff --git a/Data/Attoparsec/Text/Internal.hs b/Data/Attoparsec/Text/Internal.hs
--- a/Data/Attoparsec/Text/Internal.hs
+++ b/Data/Attoparsec/Text/Internal.hs
@@ -176,7 +176,7 @@
          | T.null ft         -> suspended s s t pos more lose succ
          | otherwise         -> lose t pos more [] "string"
        Just (pfx,ssfx,tsfx)
-         | T.null ssfx       -> let l = Pos (T.lengthWord16 pfx)
+         | T.null ssfx       -> let l = Pos (Buf.lengthCodeUnits pfx)
                                 in succ t (pos + l) more (substring pos l t)
          | not (T.null tsfx) -> lose t pos more [] "string"
          | otherwise         -> suspended s ssfx t pos more lose succ
@@ -195,7 +195,7 @@
       in case T.commonPrefixes s0 s of
         Nothing         -> lose t pos more [] "string"
         Just (_pfx,ssfx,tsfx)
-          | T.null ssfx -> let l = Pos (T.lengthWord16 s000)
+          | T.null ssfx -> let l = Pos (Buf.lengthCodeUnits s000)
                            in succ t (pos + l) more (substring pos l t)
           | T.null tsfx -> stringSuspended f s000 ssfx t pos more lose succ
           | otherwise   -> lose t pos more [] "string"
@@ -445,12 +445,12 @@
 
 -- | Terminal failure continuation.
 failK :: Failure a
-failK t (Pos pos) _more stack msg = Fail (Buf.dropWord16 pos t) stack msg
+failK t (Pos pos) _more stack msg = Fail (Buf.dropCodeUnits pos t) stack msg
 {-# INLINE failK #-}
 
 -- | Terminal success continuation.
 successK :: Success a a
-successK t (Pos pos) _more a = Done (Buf.dropWord16 pos t) a
+successK t (Pos pos) _more a = Done (Buf.dropCodeUnits pos t) a
 {-# INLINE successK #-}
 
 -- | Run a parser.
@@ -477,7 +477,7 @@
 
 get :: Parser Text
 get = T.Parser $ \t pos more _lose succ ->
-  succ t pos more (Buf.dropWord16 (fromPos pos) t)
+  succ t pos more (Buf.dropCodeUnits (fromPos pos) t)
 {-# INLINE get #-}
 
 endOfChunk :: Parser Bool
diff --git a/attoparsec.cabal b/attoparsec.cabal
--- a/attoparsec.cabal
+++ b/attoparsec.cabal
@@ -1,5 +1,5 @@
 name:            attoparsec
-version:         0.14.2
+version:         0.14.3
 license:         BSD3
 license-file:    LICENSE
 category:        Text, Parsing
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,57 +1,61 @@
-0.14.2
+# 0.14.3
 
 * Support for GHC 9.2.1
 
-0.14.1
+# 0.14.2
 
+* Support for GHC 9.2.1
+
+# 0.14.1
+
 * Added `Data.Attoparsec.ByteString.getChunk`.
 
-0.14.0
+# 0.14.0
 
 * Added `Data.Attoparsec.ByteString.takeWhileIncluding`.
 * Make `Data.Attoparsec.{Text,ByteString}.Lazy.parseOnly` accept lazy input.
 
-0.13.2.1
+# 0.13.2.1
 
 * Improved performance of `Data.Attoparsec.Text.asciiCI`
 
-0.13.2.0
+# 0.13.2.0
 
 * `pure` is now strict in `Position`
 
-0.13.1.0
+# 0.13.1.0
 
 * `runScanner` now correctly returns the final state
   (https://github.com/bos/attoparsec/issues/105).
 * `Parser`, `ZeptoT`, `Buffer`, and `More` now expose `Semigroup` instances.
 * `Parser`, and `ZeptoT` now expose `MonadFail` instances.
 
-0.13.0.2
+# 0.13.0.2
 
 * Restore the fast specialised character set implementation for Text
 * Move testsuite from test-framework to tasty
 * Performance optimization of takeWhile and takeWhile1
 
-0.13.0.1
+# 0.13.0.1
 
 * Fixed a bug in the implementations of inClass and notInClass for
   Text (https://github.com/bos/attoparsec/issues/103)
 
-0.13.0.0
+# 0.13.0.0
 
 * Made the parser type in the Zepto module a monad transformer
   (needed by aeson's string unescaping parser).
 
-0.12.1.6
+# 0.12.1.6
 
 * Fixed a case folding bug in the ByteString version of stringCI.
 
-0.12.1.5
+# 0.12.1.5
 
 * Fixed an indexing bug in the new Text implementation of string,
   reported by Michel Boucey.
 
-0.12.1.4
+# 0.12.1.4
 
 * Fixed a case where the string parser would consume an unnecessary
   amount of input before failing a match, when it could bail much
@@ -60,29 +64,29 @@
 * Added more context to error messages
   (https://github.com/bos/attoparsec/pull/79)
 
-0.12.1.3
+# 0.12.1.3
 
 * Fixed incorrect tracking of Text lengths
   (https://github.com/bos/attoparsec/issues/80)
 
-0.12.1.2
+# 0.12.1.2
 
 * Fixed the incorrect tracking of capacity if the initial buffer was
   empty (https://github.com/bos/attoparsec/issues/75)
 
-0.12.1.1
+# 0.12.1.1
 
 * Fixed a data corruption bug that occurred under some circumstances
   if a buffer grew after prompting for more input
   (https://github.com/bos/attoparsec/issues/74)
 
-0.12.1.0
+# 0.12.1.0
 
 * Now compatible with GHC 7.9
 
 * Reintroduced the Chunk class, used by the parsers package
 
-0.12.0.0
+# 0.12.0.0
 
 * A new internal representation makes almost all real-world parsers
   faster, sometimes by big margins.  For example, parsing JSON data
@@ -104,12 +108,12 @@
 * A few obsolete modules and functions have been marked as deprecated.
   They will be removed from the next major release.
 
-0.11.3.0
+# 0.11.3.0
 
 * New function scientific is compatible with rational, but parses
   integers more efficiently (https://github.com/bos/aeson/issues/198)
 
-0.11.2.0
+# 0.11.2.0
 
 * The new Chunk typeclass allows for some code sharing with Ed
   Kmett's parsers package: http://hackage.haskell.org/package/parsers
@@ -117,8 +121,7 @@
 * New function runScanner generalises scan to return the final state
   of the scanner as well as the input consumed.
 
-
-0.11.1.0
+# 0.11.1.0
 
 * New dependency: the scientific package.  This allows us to parse
   numbers much more efficiently.
diff --git a/tests/QC/Buffer.hs b/tests/QC/Buffer.hs
--- a/tests/QC/Buffer.hs
+++ b/tests/QC/Buffer.hs
@@ -51,7 +51,7 @@
 b_length (BP _ts t buf) = B.length t === BB.length buf
 
 t_length :: BPT -> Property
-t_length (BP _ts t buf) = T.lengthWord16 t === BT.length buf
+t_length (BP _ts t buf) = BT.lengthCodeUnits t === BT.length buf
 
 b_unsafeIndex :: BPB -> Gen Property
 b_unsafeIndex (BP _ts t buf) = do
@@ -61,14 +61,14 @@
 
 t_iter :: BPT -> Gen Property
 t_iter (BP _ts t buf) = do
-  let l = T.lengthWord16 t
+  let l = BT.lengthCodeUnits t
   i <- choose (0,l-1)
   let it (T.Iter c q) = (c,q)
   return $ l === 0 .||. it (T.iter t i) === it (BT.iter buf i)
 
 t_iter_ :: BPT -> Gen Property
 t_iter_ (BP _ts t buf) = do
-  let l = T.lengthWord16 t
+  let l = BT.lengthCodeUnits t
   i <- choose (0,l-1)
   return $ l === 0 .||. T.iter_ t i === BT.iter_ buf i
 
@@ -77,10 +77,16 @@
   i <- choose (0, B.length t)
   return $ B.unsafeDrop i t === BB.unsafeDrop i buf
 
-t_dropWord16 :: BPT -> Gen Property
-t_dropWord16 (BP _ts t buf) = do
-  i <- choose (0, T.lengthWord16 t)
-  return $ T.dropWord16 i t === BT.dropWord16 i buf
+t_dropCodeUnits :: BPT -> Gen Property
+t_dropCodeUnits (BP _ts t buf) = do
+  i <- choose (0, BT.lengthCodeUnits t)
+  return $ dropCodeUnits i t === BT.dropCodeUnits i buf
+  where
+#if MIN_VERSION_text(2,0,0)
+    dropCodeUnits = T.dropWord8
+#else
+    dropCodeUnits = T.dropWord16
+#endif
 
 tests :: [TestTree]
 tests = [
@@ -92,5 +98,5 @@
   , testProperty "t_iter" t_iter
   , testProperty "t_iter_" t_iter_
   , testProperty "b_unsafeDrop" b_unsafeDrop
-  , testProperty "t_dropWord16" t_dropWord16
+  , testProperty "t_dropCodeUnits" t_dropCodeUnits
   ]