diff --git a/.github/workflows/packcheck.yml b/.github/workflows/packcheck.yml
index 922ac74..e338309 100644
--- a/.github/workflows/packcheck.yml
+++ b/.github/workflows/packcheck.yml
@@ -1,4 +1,4 @@
-# packcheck-0.5.1
+# packcheck-0.7.0
 # You can use any of the options supported by packcheck as environment
 # variables here.  See https://github.com/composewell/packcheck for all
 # options and their explanation.
@@ -23,219 +23,148 @@ on:
 jobs:
   build:
     name: ${{ matrix.name }}
-
     env:
       # ------------------------------------------------------------------------
       # Common options
       # ------------------------------------------------------------------------
       # GHC_OPTIONS: "-Werror"
+      GHCUP_VERSION: 0.1.20.0
+      DOCSPEC_URL: https://github.com/phadej/cabal-extras/releases/download/cabal-docspec-0.0.0.20210111/cabal-docspec-0.0.0.20210111.xz
+      DOCSPEC_OPTIONS: "--timeout 60"
       CABAL_REINIT_CONFIG: y
       LC_ALL: C.UTF-8
 
-      # ------------------------------------------------------------------------
-      # What to build
-      # ------------------------------------------------------------------------
-      # DISABLE_TEST: "y"
-      # DISABLE_BENCH: "y"
-      # DISABLE_DOCS: "y"
-      # DISABLE_SDIST_BUILD: "y"
-      # DISABLE_SDIST_GIT_CHECK: "y"
-      # DISABLE_DIST_CHECKS: "y"
-
-      # ------------------------------------------------------------------------
-      # stack options
-      # ------------------------------------------------------------------------
-      # Note requiring a specific version of stack using STACKVER may fail due to
-      # github API limit while checking and upgrading/downgrading to the specific
-      # version.
-      #STACKVER: "1.6.5"
-      #STACK_UPGRADE: "y"
-      #RESOLVER: ${{ matrix.resolver }}
+      STACK_UPGRADE: "y"
 
-      # ------------------------------------------------------------------------
-      # cabal options
-      # ------------------------------------------------------------------------
       CABAL_CHECK_RELAX: y
-      CABAL_HACKAGE_MIRROR: "hackage.haskell.org:http://hackage.fpcomplete.com"
-      # CABAL_PROJECT: "cabal.project.user"
-      DISABLE_SDIST_BUILD: "n"
-
-      # ------------------------------------------------------------------------
-      # Where to find the required tools
-      # ------------------------------------------------------------------------
-      PATH: /opt/ghc/bin:/sbin:/usr/sbin:/bin:/usr/bin
-      #TOOLS_DIR: /opt
+      CABAL_HACKAGE_MIRROR: hackage.haskell.org:http://hackage.fpcomplete.com
 
-      # ------------------------------------------------------------------------
-      # Location of packcheck.sh (the shell script invoked to perform CI tests ).
-      # ------------------------------------------------------------------------
-      # You can either commit the packcheck.sh script at this path in your repo or
-      # you can use it by specifying the PACKCHECK_REPO_URL option below in which
-      # case it will be automatically copied from the packcheck repo to this path
-      # during CI tests. In any case it is finally invoked from this path.
       PACKCHECK: "./packcheck.sh"
-      # If you have not committed packcheck.sh in your repo at PACKCHECK
-      # then it is automatically pulled from this URL.
       PACKCHECK_GITHUB_URL: "https://raw.githubusercontent.com/composewell/packcheck"
-      PACKCHECK_GITHUB_COMMIT: "ccc55fd4b895e842ca6e2d8ac63aa4acc1c3209a"
+      PACKCHECK_GITHUB_COMMIT: "7c4e1ab7a59b5ed6e92cfd0da67460a6116be4ac"
 
-      # ------------------------------------------------------------------------
-      # Final build variables
-      # ------------------------------------------------------------------------
-      PACKCHECK_COMMAND: ${{ matrix.command }} ${{ matrix.pack_options }}
+      BUILD: ${{ matrix.build }}
+      GHCVER: ${{ matrix.ghc_version }}
+      #RESOLVER: ${{ matrix.resolver }}
+      CABAL_BUILD_OPTIONS: ${{ matrix.cabal_build_options }}
+      CABAL_PROJECT: ${{ matrix.cabal_project }}
+      DISABLE_DOCS: ${{ matrix.disable_docs }}
+      #DISABLE_SDIST_BUILD: ${{ matrix.disable_sdist_build }}
+      #DISABLE_SDIST_BUILD: "y"
+      HLINT_VERSION: 3.6.1
+      HLINT_OPTIONS: ${{ matrix.hlint_options }}
+      HLINT_TARGETS: ${{ matrix.hlint_targets }}
 
     runs-on: ${{ matrix.runner }}
-    continue-on-error: ${{ matrix.ignore_error }}
     strategy:
       fail-fast: false
       matrix:
-
         include:
-
-          - name: 9.10.1+streamly-core-master
+          - name: 9.10.1-Werror
             ghc_version: 9.10.1
-            command: cabal-v2
+            build: cabal
             runner: ubuntu-latest
-            cabal-version: 3.8.1.0
-            ignore_error: false
-            pack_options: >-
-              CABAL_PROJECT=cabal.project.Werror
+            cabal-version: 3.10.2.0
+            cabal_project: cabal.project.Werror
 
-          - name: 9.8.1+streamly-core-0.2.2+text-2.1.1
+          - name: 9.8.1-Werror
             ghc_version: 9.8.1
-            command: cabal-v2
+            build: cabal
             runner: ubuntu-latest
-            cabal-version: 3.8.1.0
-            pack_options: >-
-              CABAL_BUILD_OPTIONS="
-              --constraint='streamly-core==0.2.2'
-              --constraint='text==2.1.1'
-              "
-            ignore_error: false
-
-          - name: 9.6.2+streamly-core-0.2.2+text-2.1
-            ghc_version: 9.6.2
-            command: cabal-v2
+            cabal-version: 3.10.2.0
+            cabal_project: cabal.project.Werror
+
+          - name: hlint
+            build: hlint
+            hlint_options: "lint"
+            hlint_targets: "src"
             runner: ubuntu-latest
-            cabal-version: 3.8.1.0
-            ignore_error: true
-            pack_options: >-
-              CABAL_BUILD_OPTIONS="
-              --constraint='streamly-core==0.2.2'
-              --constraint='text==2.1'
-              "
-
-          - name: 9.4.4+streamly-core-0.2.1+text-2.0.2
-            ghc_version: 9.4.4
-            command: cabal-v2
+            cabal-version: 3.2
+            cabal_project: cabal.project.Werror
+
+          - name: 9.6.3-macos
+            runner: macos-latest
+            ghc_version: 9.6.3
+            build: cabal
+            cabal-version: 3.10.1.0
+            cabal_project: cabal.project.Werror
+
+          - name: 9.4.4
             runner: ubuntu-latest
+            ghc_version: 9.4.4
+            build: cabal
             cabal-version: 3.8.1.0
-            ignore_error: false
-            pack_options: >-
-              CABAL_BUILD_OPTIONS="
-              --constraint='streamly-core==0.2.1'
-              --constraint='text==2.0.2'
-              "
-
-          - name: 9.2.7+streamly-core-0.2.1+text-2.0.1
-            ghc_version: 9.2.7
-            command: cabal-v2
+            cabal_project: cabal.project.Werror
+
+          - name: 9.4.4
             runner: ubuntu-latest
-            cabal-version: 3.6.2.0
-            ignore_error: false
-            pack_options: >-
-              CABAL_BUILD_OPTIONS="
-              --constraint='streamly-core==0.2.1'
-              --constraint='text==2.0.1'
-              "
-
-          - name: 9.0.1+streamly-core-0.2.0+text-2.0
-            ghc_version: 9.0.1
-            command: cabal-v2
+            ghc_version: 9.4.4
+            build: cabal
+            cabal-version: 3.8.1.0
+            cabal_project: cabal.project.Werror
+
+          - name: 9.2.7
             runner: ubuntu-latest
-            cabal-version: 3.2
-            ignore_error: false
-            pack_options: >-
-              CABAL_BUILD_OPTIONS="
-              --constraint='streamly-core==0.2.0'
-              --constraint='text==2.0'
-              "
+            ghc_version: 9.2.7
+            build: cabal
+            cabal-version: 3.6
+            cabal_project: cabal.project.Werror
 
           - name: 8.10.7
-            ghc_version: 8.10.7
-            command: cabal-v2
             runner: ubuntu-latest
-            cabal-version: 3.2
-            ignore_error: false
-
-          - name: 8.10.7+macOS
             ghc_version: 8.10.7
-            command: cabal-v2
-            runner: macos-latest
-            cabal_version: 3.4
-            ignore_error: false
+            build: cabal
+            cabal-version: 3.2
+            cabal_project: cabal.project.Werror
+            disable_docs: y
 
           - name: 8.8.4
-            ghc_version: 8.8.4
-            command: cabal-v2
             runner: ubuntu-latest
+            ghc_version: 8.8.4
+            build: cabal
             cabal-version: 3.2
-            ignore_error: false
+            disable_docs: y
 
           - name: 8.6.5
-            ghc_version: 8.6.5
-            command: cabal-v2
             runner: ubuntu-latest
+            ghc_version: 8.6.5
+            build: cabal
             cabal-version: 3.2
-            ignore_error: false
-
-          - name: hlint
-            ghc_version: 8.8.4
-            command: cabal-v2
-            runner: ubuntu-latest
-            pack_options: >-
-              HLINT_OPTIONS="lint"
-              HLINT_TARGETS="src"
-            cabal-version: 3.2
-            ignore_error: false
+            disable_docs: y
 
     steps:
     - uses: actions/checkout@v2
 
-    - uses: haskell/actions/setup@v1
-      with:
-        ghc-version: ${{ matrix.ghc_version }}
-
-    - uses: actions/cache@v2
-      name: Cache common directories
+    - uses: actions/cache@v4
+      name: Restore cache
       with:
         path: |
-          ~/.cabal
-          ~/.ghc
           ~/.local
+          ~/.cabal
           ~/.stack
-        key: ${{ matrix.ghc_version }}-${{ matrix.runner }}
-
-    - name: Run installer
-      if: ${{ matrix.installer != '' }}
-      run: ${{ matrix.installer }}
-
-    - name: Setup stack
-      if: ${{ matrix.command == 'stack' }}
-      run: |
-        # required for packcheck
-        sudo apt-get install -y curl
-        # required for outbound https for stack and for stack setup
-        sudo apt-get install -y netbase xz-utils make
+          .stack-work
+        key: ${{ runner.os }}-${{ matrix.name }}
 
     - name: Download packcheck
       run: |
-        # Get packcheck if needed
-        CURL=$(which curl)
-        PACKCHECK_URL=${PACKCHECK_GITHUB_URL}/${PACKCHECK_GITHUB_COMMIT}/packcheck.sh
-        if test ! -e "$PACKCHECK"; then $CURL -sL -o "$PACKCHECK" $PACKCHECK_URL; fi;
-        chmod +x $PACKCHECK
+        # If a custom stack-yaml is specified, replace the default with that
+        #if test -e "$STACK_YAML"; then rm -f stack.yaml && ln -sv $STACK_YAML stack.yaml; else true; fi
+        #unset STACK_YAML
+
+        if test ! -e "$PACKCHECK"
+        then
+          if test -z "$PACKCHECK_GITHUB_COMMIT"
+          then
+              die "PACKCHECK_GITHUB_COMMIT is not specified."
+          fi
+          PACKCHECK_URL=${PACKCHECK_GITHUB_URL}/${PACKCHECK_GITHUB_COMMIT}/packcheck.sh
+          curl --fail -sL -o "$PACKCHECK" $PACKCHECK_URL || exit 1
+          chmod +x $PACKCHECK
+        elif test ! -x "$PACKCHECK"
+        then
+            chmod +x $PACKCHECK
+        fi
 
     - name: Run packcheck
       run: |
-        bash -c "$PACKCHECK $PACKCHECK_COMMAND"
+          bash -c "$PACKCHECK $BUILD"
diff --git a/README.md b/README.md
index fcca492..f4e8985 100644
--- a/README.md
+++ b/README.md
@@ -5,9 +5,8 @@ Library for streamly and text interoperation.
 This library is to enable interoperation of streamly with existing code that
 uses `Text`.
 
-The package provides APIs to interconvert between strict `Text` and
-streamly `Array Word16` and between lazy `Text` and stream of `Array
-Word16`.
+The package provides APIs to interconvert between strict `Text` and streamly
+`Array Word8` and between lazy `Text` and stream of `Array Word8`.
 
 The interconversion in the case of strict `Text` and streamly `Array Word8` has
 no overhead.
diff --git a/cabal.project.Werror b/cabal.project.Werror
index 0559699..d4610aa 100644
--- a/cabal.project.Werror
+++ b/cabal.project.Werror
@@ -3,13 +3,13 @@ packages: streamly-text.cabal
 package streamly-text
   ghc-options: -Werror
 
-source-repository-package
-   type: git
-   location: https://github.com/composewell/streamly.git
-   tag: master
+-- source-repository-package
+--    type: git
+--    location: https://github.com/composewell/streamly.git
+--    tag: master
 
-source-repository-package
-  type: git
-  location: https://github.com/composewell/streamly.git
-  tag: master
-  subdir: core
+-- source-repository-package
+--   type: git
+--   location: https://github.com/composewell/streamly.git
+--   tag: master
+--   subdir: core
diff --git a/src/Streamly/External/Text.hs b/src/Streamly/Compat/Text.hs
similarity index 81%
rename from src/Streamly/External/Text.hs
rename to src/Streamly/Compat/Text.hs
index 610a783..7ddca95 100644
--- a/src/Streamly/External/Text.hs
+++ b/src/Streamly/Compat/Text.hs
@@ -3,13 +3,13 @@
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE BangPatterns #-}
 
-module Streamly.External.Text
+module Streamly.Compat.Text
   ( toArray
   , unsafeFromArray
 
   , reader
 
-  , unsafeCreateOf
+  -- , unsafeCreateOf
   , unsafeCreate
   )
 where
@@ -58,10 +58,13 @@ toArray (Text (TArr.ByteArray _) _ len)
 toArray (Text (TArr.ByteArray barr#) off8 len8) =
     Array (MutByteArray (unsafeCoerce# barr#)) off8 (off8 + len8)
 
--- | Treat an an array of 'Word8' as 'Text'. This function is unsafe and the
--- onus is on the caller to check the sanity of 'Array' 'Word8'. This function
--- unwraps the 'Array' and wraps it with 'Text' constructors and hence the
--- operation is performed in constant time.
+-- | Treat an an array of 'Word8' as 'Text'.
+--
+-- This function is unsafe: the caller must ensure that the 'Array' 'Word8' is a
+-- valid UTF-8 encoding.
+--
+-- This function unwraps the 'Array' and wraps it with 'Text' constructors and
+-- hence the operation is performed in constant time.
 {-# INLINE unsafeFromArray #-}
 unsafeFromArray :: Array Word8 -> Text
 unsafeFromArray Array {..}
@@ -80,9 +83,9 @@ reader :: Monad m => Unfold m Text Word8
 reader = lmap toArray Array.reader
 
 -- | Fold a stream of Word8 to a 'Text' of given size in bytes.
-{-# INLINE unsafeCreateOf #-}
-unsafeCreateOf :: MonadIO m => Int -> Fold m Word8 Text
-unsafeCreateOf i = unsafeFromArray <$> CREATE_OF i
+{-# INLINE _unsafeCreateOf #-}
+_unsafeCreateOf :: MonadIO m => Int -> Fold m Word8 Text
+_unsafeCreateOf i = unsafeFromArray <$> CREATE_OF i
 
 -- | Fold a stream of Word8 to a 'Text' of appropriate size.
 {-# INLINE unsafeCreate #-}
diff --git a/src/Streamly/External/Text/Lazy.hs b/src/Streamly/Compat/Text/Lazy.hs
similarity index 89%
rename from src/Streamly/External/Text/Lazy.hs
rename to src/Streamly/Compat/Text/Lazy.hs
index 6053c31..cf4995f 100644
--- a/src/Streamly/External/Text/Lazy.hs
+++ b/src/Streamly/Compat/Text/Lazy.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE CPP #-}
 
-module Streamly.External.Text.Lazy
+module Streamly.Compat.Text.Lazy
   ( chunkReader
   , reader
 
@@ -20,7 +20,7 @@ import Data.Text.Internal.Lazy (Text(..), chunk)
 import Streamly.Internal.Data.Stream (Step(..))
 import Streamly.Internal.Data.Unfold (Unfold(..))
 
-import qualified Streamly.External.Text as Strict
+import qualified Streamly.Compat.Text as Strict
 import qualified Streamly.Data.Array as Array
 import qualified Streamly.Data.Unfold as Unfold
 import qualified Streamly.Data.Stream as Stream
@@ -55,8 +55,8 @@ toChunks = Stream.unfold chunkReader
 
 -- | Convert a serial stream of 'Array' 'Word8' to a lazy 'Text'.
 --
--- This function is unsafe and the onus is on the caller to check the sanity of
--- the stream of 'Array' 'Word8'.
+-- This function is unsafe: the caller must ensure that each 'Array' 'Word8'
+-- element in the stream is a valid UTF-8 encoding.
 --
 -- IMPORTANT NOTE: This function is lazy only for lazy monads
 -- (e.g. Identity). For strict monads (e.g. /IO/) it consumes the entire input
@@ -65,8 +65,8 @@ toChunks = Stream.unfold chunkReader
 --
 -- For strict monads like /IO/ you could create a newtype wrapper to make the
 -- monad bind operation lazy and lift the stream to that type using hoist, then
--- you can use this function to generate the bytestring lazily. For example you
--- can wrap the /IO/ type to make the bind lazy like this:
+-- you can use this function to generate the text lazily. For example you can
+-- wrap the /IO/ type to make the bind lazy like this:
 --
 -- @
 -- newtype LazyIO a = LazyIO { runLazy :: IO a } deriving (Functor, Applicative)
diff --git a/streamly-text.cabal b/streamly-text.cabal
index 99d4fbb..d62806a 100644
--- a/streamly-text.cabal
+++ b/streamly-text.cabal
@@ -26,8 +26,8 @@ common compile-options
 
 library
   import:              compile-options
-  exposed-modules:     Streamly.External.Text
-                     , Streamly.External.Text.Lazy
+  exposed-modules:     Streamly.Compat.Text
+                     , Streamly.Compat.Text.Lazy
   build-depends:       base          >=4.7   && <5
                      , streamly-core >=0.2.0 && <0.3.1
                      , text          >=2.0   && <2.1.2
diff --git a/test/Main.hs b/test/Main.hs
index 472f2c5..c70a66c 100644
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -10,13 +10,14 @@ import Test.QuickCheck.Instances.Text ()
 import System.IO (hClose)
 import Data.Functor.Identity (Identity(..))
 
-import qualified Streamly.Internal.Data.Array as Array (castUnsafe)
+import qualified Streamly.Internal.Data.Array as Array (unsafeCast)
 
 import qualified Data.Text as BS
 import qualified Data.Text.Lazy as BSL
-import qualified Streamly.FileSystem.File as File
-import qualified Streamly.External.Text as Strict
-import qualified Streamly.External.Text.Lazy as Lazy
+import qualified Streamly.FileSystem.FileIO as File
+import qualified Streamly.FileSystem.Path as Path
+import qualified Streamly.Compat.Text as Strict
+import qualified Streamly.Compat.Text.Lazy as Lazy
 import qualified Streamly.Data.Stream as Stream
 
 pipeline ::
@@ -55,11 +56,12 @@ writeRead :: Int -> IO ()
 writeRead n = do
     str <- sequence $ replicate n (randomIO :: IO Char)
     let txt = BSL.pack str
-    withSystemTempFile "temp" $ \fp hdl -> do
+    withSystemTempFile "temp" $ \fp0 hdl -> do
+        fp <- Path.fromString fp0
         hClose hdl
-        let strm = fmap Array.castUnsafe $ Lazy.toChunks txt
+        let strm = fmap Array.unsafeCast $ Lazy.toChunks txt
         Stream.fold (File.writeChunks fp) strm
-        let strm1 = fmap Array.castUnsafe $ File.readChunks fp
+        let strm1 = fmap Array.unsafeCast $ File.readChunks fp
         txt1 <- Lazy.unsafeFromChunksIO strm1
         txt1 `shouldBe` txt