diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4dec9d4..cf53a8e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,14 +13,17 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
-        cabal: ["3.2"]
+        cabal: ["3.4"]
         ghc:
           - "8.2.2"
           - "8.4.4"
           - "8.6.5"
           - "8.8.4"
-          - "8.10.3"
+          - "8.10.4"
+          - "9.0.1"
         exclude:
+          - os: macOS-latest
+            ghc: 8.10.4
           - os: macOS-latest
             ghc: 8.8.4
           - os: macOS-latest
@@ -30,6 +33,8 @@ jobs:
           - os: macOS-latest
             ghc: 8.2.2
 
+          - os: windows-latest
+            ghc: 8.10.4
           - os: windows-latest
             ghc: 8.8.4
           - os: windows-latest
@@ -75,7 +80,7 @@ jobs:
     strategy:
       matrix:
         stack: ["2.5"]
-        ghc: ["8.10.3"]
+        ghc: ["8.10.4"]
 
     steps:
     - uses: actions/checkout@v2
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c9ff2b5..cca0f25 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,7 +27,9 @@ The changelog is available [on GitHub][2].
           , relude
   ```
 
-* Upgrade to GHC-8.10.3, GHC-8.8.4.
+* [#345](https://github.com/kowainik/relude/issues/345):
+  Support GHC-9.0.
+* Upgrade to GHC-8.10.4, GHC-8.8.4.
 * Add `infinitely` as more strictly typed `forever`.
 * Remove `Eq` constraint on `universeNonEmpty`
 * Add `maybeAt`, `!!?` with its arguments flipped.
@@ -41,12 +43,13 @@ The changelog is available [on GitHub][2].
   module created that is exported in the main `Relude` module by default.
 
   __Migration guide:__ If you were using any of these functions you can now
-  remove `Relude.Extra.Enum` from your imports and explicit `mixins` section 
+  remove `Relude.Extra.Enum` from your imports and explicit `mixins` section
   as they are available for you with the `Relude` module.
 * [#347](https://github.com/kowainik/relude/issues/347):
   Add `ordNubOn` function.
 * [#268](https://github.com/kowainik/relude/issues/268):
   Drop support of GHC-8.0.2.
+* Add lifted `readFile'` function.
 
 ## 0.7.0.0 — May 14, 2020
 
diff --git a/relude.cabal b/relude.cabal
index ebe385d..cdf7206 100644
--- a/relude.cabal
+++ b/relude.cabal
@@ -95,7 +95,8 @@ tested-with:         GHC == 8.2.2
                      GHC == 8.4.4
                      GHC == 8.6.5
                      GHC == 8.8.4
-                     GHC == 8.10.3
+                     GHC == 8.10.4
+                     GHC == 9.0.1
 
 
 source-repository head
@@ -103,7 +104,7 @@ source-repository head
   location: git@github.com:kowainik/relude.git
 
 common common-options
-  build-depends:       base >= 4.10 && < 4.15
+  build-depends:       base >= 4.10 && < 4.16
 
   ghc-options:         -Wall
                        -Wcompat
@@ -223,7 +224,7 @@ library
   build-depends:       bytestring >= 0.10 && < 0.12
                      , containers >= 0.5.7 && < 0.7
                      , deepseq ^>= 1.4
-                     , ghc-prim >= 0.4.0.0 && < 0.7
+                     , ghc-prim >= 0.4.0.0 && < 0.8
                      , hashable >= 1.2 && < 1.4
                      , mtl ^>= 2.2
                      , stm >= 2.4 && < 2.6
diff --git a/src/Relude/Lifted/File.hs b/src/Relude/Lifted/File.hs
index 46956a3..292259c 100644
--- a/src/Relude/Lifted/File.hs
+++ b/src/Relude/Lifted/File.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP  #-}
 {-# LANGUAGE Safe #-}
 
 {- |
@@ -14,6 +15,9 @@ Lifted versions of functions working with files and common IO.
 
 module Relude.Lifted.File
     ( readFile
+#if ( __GLASGOW_HASKELL__ >= 900 )
+    , readFile'
+#endif
     , writeFile
     , appendFile
     ) where
@@ -32,6 +36,17 @@ readFile = liftIO . IO.readFile
 {-# SPECIALIZE readFile :: FilePath -> IO String #-}
 {-# INLINE readFile #-}
 
+#if ( __GLASGOW_HASKELL__ >= 900 )
+{- | Lifted version of 'IO.readFile''. Strict version of 'readFile'.
+
+@since x.x.x.x
+-}
+readFile' :: MonadIO m => FilePath -> m String
+readFile' = liftIO . IO.readFile'
+{-# SPECIALIZE readFile' :: FilePath -> IO String #-}
+{-# INLINE readFile' #-}
+#endif
+
 -- | Lifted version of 'IO.writeFile'.
 writeFile :: MonadIO m => FilePath -> String -> m ()
 writeFile p= liftIO . IO.writeFile p
diff --git a/stack.yaml b/stack.yaml
index ab7f113..fd834e1 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1 +1 @@
-resolver: lts-17.0
+resolver: lts-17.5