diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 5c150db..e9fc125 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -20,14 +20,10 @@ jobs:
       matrix:
         os:
           - ubuntu-latest
+          - macos-12
         ghc:
-          - '9.4'
-          - '9.6'
-          - '9.8'
           - '9.10'
-        include:
-          - os: macos-12
-            ghc: system
+
     steps:
       - uses: actions/checkout@v3
       - uses: hspec/setup-haskell@v1
@@ -54,12 +50,13 @@ jobs:
         run: cabal build all
 
       - shell: bash
-        run: echo | cabal repl sensei --build-depends hspec-meta
-
-      - shell: bash
-        run: cabal exec -- $(cabal list-bin spec) --times --print-slow
-        env:
-          HSPEC_OPTIONS: --color
+        run: |
+          for GHC in 9.4 9.6 9.8 9.10
+          do
+            ghcup install ghc $GHC --no-set
+            cabal install -z -w ghc-$GHC --package-env=./$GHC.env --lib hspec hspec-meta
+            SENSEI_GHC=ghc-$GHC GHC_ENVIRONMENT=$(pwd)/$GHC.env $(cabal list-bin spec)
+          done
 
   success:
     needs: build
diff --git a/cabal.project b/cabal.project
index a4eadbd..63f8c7f 100644
--- a/cabal.project
+++ b/cabal.project
@@ -1,3 +1,5 @@
+with-compiler: ghc-9.10.1
+
 packages:
   sensei.cabal
 
diff --git a/package.yaml b/package.yaml
index 5f4548d..9482e98 100644
--- a/package.yaml
+++ b/package.yaml
@@ -40,7 +40,7 @@ dependencies:
   - async
   - containers
   - transformers
-  - mtl
+  - mtl >= 2.3.1
   - aeson
   - yaml
   - casing
diff --git a/sensei.cabal b/sensei.cabal
index 061e932..f9599d4 100644
--- a/sensei.cabal
+++ b/sensei.cabal
@@ -1,6 +1,6 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.36.0.
+-- This file has been generated from package.yaml by hpack version 0.37.0.
 --
 -- see: https://github.com/sol/hpack
 
@@ -63,7 +63,7 @@ executable seito
     , fsnotify ==0.4.*
     , http-client >=0.5.0
     , http-types
-    , mtl
+    , mtl >=2.3.1
     , network
     , process
     , stm
@@ -121,7 +121,7 @@ executable sensei
     , fsnotify ==0.4.*
     , http-client >=0.5.0
     , http-types
-    , mtl
+    , mtl >=2.3.1
     , network
     , process
     , stm
@@ -179,7 +179,7 @@ executable sensei-web
     , fsnotify ==0.4.*
     , http-client >=0.5.0
     , http-types
-    , mtl
+    , mtl >=2.3.1
     , network
     , process
     , stm
@@ -260,7 +260,7 @@ test-suite spec
     , http-client >=0.5.0
     , http-types
     , mockery
-    , mtl
+    , mtl >=2.3.1
     , network
     , process
     , stm
diff --git a/src/Trigger.hs b/src/Trigger.hs
index 132d602..77b8232 100644
--- a/src/Trigger.hs
+++ b/src/Trigger.hs
@@ -14,12 +14,8 @@ module Trigger (
 
 import           Imports
 
-#if MIN_VERSION_mtl(2,3,1)
 import           Control.Monad.Trans.Writer.CPS (runWriterT)
 import           Control.Monad.Writer.CPS hiding (pass)
-#else
-import           Control.Monad.Writer.Strict hiding (pass)
-#endif
 
 import           Control.Monad.Except
 
diff --git a/test/Language/Haskell/GhciWrapperSpec.hs b/test/Language/Haskell/GhciWrapperSpec.hs
index 54bad2d..d7f9bad 100644
--- a/test/Language/Haskell/GhciWrapperSpec.hs
+++ b/test/Language/Haskell/GhciWrapperSpec.hs
@@ -121,7 +121,7 @@ spec = do
 
     context "with -XNoImplicitPrelude" $ do
       it "works" $ withInterpreter ["-XNoImplicitPrelude"] $ \ ghci -> do
-        Interpreter.eval ghci "putStrLn \"foo\"" >>= (`shouldContain` "Variable not in scope: putStrLn")
+        (unwords . map (dropWhile isSpace) . lines <$> Interpreter.eval ghci "putStrLn \"foo\"") >>= (`shouldContain` "Variable not in scope: putStrLn")
         Interpreter.eval ghci "23" `shouldReturn` "23\n"
 
   describe "reload" do
diff --git a/test/TriggerSpec.hs b/test/TriggerSpec.hs
index 9be4a19..26c3ce7 100644
--- a/test/TriggerSpec.hs
+++ b/test/TriggerSpec.hs
@@ -3,6 +3,8 @@ module TriggerSpec (spec) where
 
 import           Helper
 
+import qualified Data.Text as Text
+
 import qualified Session
 import           Session (Session)
 import           Language.Haskell.GhciWrapper (Config(..))
@@ -11,7 +13,7 @@ import           Trigger hiding (trigger, triggerAll)
 import qualified Trigger
 
 normalize :: String -> [String]
-normalize = normalizeTiming . lines
+normalize = normalizeTiming . lines . forGhc9dot4
   where
     normalizeTiming :: [String] -> [String]
     normalizeTiming = normalizeLine "Finished in "
@@ -23,6 +25,11 @@ normalize = normalizeTiming . lines
           | message `isPrefixOf` line = message ++ "..."
           | otherwise = line
 
+    forGhc9dot4 :: String -> String
+    forGhc9dot4 = Text.unpack
+      . Text.replace " error: Variable not in scope: " " error: [GHC-88464] Variable not in scope: "
+      . Text.pack
+
 withSession :: FilePath -> [String] -> (Session -> IO a) -> IO a
 withSession specPath args = do
   Session.withSession ghciConfig {configWorkingDirectory = Just dir} $
@@ -155,19 +162,14 @@ spec = do
       it "stops after reloading" $ \ name -> do
         withSession name [] $ \ session -> do
           writeFile name (passingSpec ++ "foo = bar")
-          (trigger session >> trigger session) `shouldReturn` (Failure, [
+
+          let
+            fitterNotNull :: [String] -> [String]
+            fitterNotNull = filter (not . null)
+
+          (fmap fitterNotNull <$> (trigger session >> trigger session)) `shouldReturn` (Failure, [
               "[1 of 1] Compiling Spec"
-#if __GLASGOW_HASKELL__ < 910
-            , ""
-#endif
-#if __GLASGOW_HASKELL__ >= 906
             , "Spec.hs:9:7: error: [GHC-88464] Variable not in scope: bar"
-#else
-            , "Spec.hs:9:7: error: Variable not in scope: bar"
-#endif
-#if __GLASGOW_HASKELL__ >= 910
-            , ""
-#endif
             , withColor Red "RELOADING FAILED"
             ])