diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,15 @@
 ## Changelog
 
+### 1.3.0.1
+
+Released 2021-02-06.
+
+- Fixed build with GHC 9.0.1 (Simon Jakobi).
+
+- Improved test-suite; fixed memory leaks in some tests.
+
+- Moved CI to GitHub Actions.
+
 ### 1.3.0
 
 Released 2020-10-16.
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,14 +1,15 @@
 # HsLua – Bindings to Lua, an embeddable scripting language
 
-[![Build Status]](https://travis-ci.com/hslua/hslua)
+[![Build status][GitHub Actions badge]][GitHub Actions]
 [![AppVeyor Status]](https://ci.appveyor.com/project/tarleb/hslua-r2y18)
 [![Hackage]](https://hackage.haskell.org/package/hslua)
 
 HsLua provides bindings, wrappers, types, and helper functions to bridge
 Haskell and Lua.
 
-[Build Status]: https://travis-ci.com/hslua/hslua.svg?branch=master
-[AppVeyor Status]: https://ci.appveyor.com/api/projects/status/ldutrilgxhpcau94/branch/master?svg=true
+[GitHub Actions badge]: https://img.shields.io/github/workflow/status/hslua/hslua/CI.svg?logo=github
+[GitHub Actions]: https://github.com/hslua/hslua/actions
+[AppVeyor Status]: https://ci.appveyor.com/api/projects/status/ldutrilgxhpcau94/branch/main?svg=true
 [Hackage]: https://img.shields.io/hackage/v/hslua.svg
 
 
diff --git a/hslua.cabal b/hslua.cabal
--- a/hslua.cabal
+++ b/hslua.cabal
@@ -1,6 +1,6 @@
 cabal-version:       2.2
 name:                hslua
-version:             1.3.0
+version:             1.3.0.1
 synopsis:            Bindings to Lua, an embeddable scripting language
 description:         HsLua provides bindings, wrappers, types, and helper
                      functions to bridge Haskell and <https://www.lua.org/ Lua>.
diff --git a/prelude/Prelude.hs b/prelude/Prelude.hs
--- a/prelude/Prelude.hs
+++ b/prelude/Prelude.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 module Prelude (
     module Prelude.Compat
   , Semigroup (..)
diff --git a/src/Foreign/Lua/Core/Auxiliary.hs b/src/Foreign/Lua/Core/Auxiliary.hs
--- a/src/Foreign/Lua/Core/Auxiliary.hs
+++ b/src/Foreign/Lua/Core/Auxiliary.hs
@@ -227,11 +227,11 @@
 tostring' :: StackIndex -> Lua B.ByteString
 tostring' n = do
   l <- Lua.state
-  e2e <- Lua.errorToException <$> Lua.errorConversion
+  e <- Lua.errorConversion
   Lua.liftIO $ alloca $ \lenPtr -> do
     cstr <- hsluaL_tolstring l n lenPtr
     if cstr == nullPtr
-      then e2e l
+      then Lua.errorToException e l
       else do
         cstrLen <- Storable.peek lenPtr
         B.packCStringLen (cstr, fromIntegral cstrLen)
diff --git a/src/Foreign/Lua/Core/Error.hs b/src/Foreign/Lua/Core/Error.hs
--- a/src/Foreign/Lua/Core/Error.hs
+++ b/src/Foreign/Lua/Core/Error.hs
@@ -77,9 +77,9 @@
 -- expected to be at the top of the stack.
 throwErrorAsException :: Lua a
 throwErrorAsException = do
-  f <- Lua.errorToException <$> Lua.errorConversion
+  e <- Lua.errorConversion
   l <- Lua.state
-  Lua.liftIO (f l)
+  Lua.liftIO (Lua.errorToException e l)
 
 -- | Alias for `throwErrorAsException`; will be deprecated in the next
 -- mayor release.
@@ -93,13 +93,14 @@
   Lua.liftLua $ \l ->
     B.unsafeUseAsCStringLen (Utf8.fromString msg) $ \(msgPtr, z) ->
       lua_pushlstring l msgPtr (fromIntegral z)
-  Lua.errorConversion >>= Lua.liftLua . Lua.errorToException
+  e <- Lua.errorConversion
+  Lua.liftLua (Lua.errorToException e)
 
 instance Alternative Lua where
   empty = throwMessage "empty"
   x <|> y = do
-    alt <- Lua.alternative <$> Lua.errorConversion
-    x `alt` y
+    e <- Lua.errorConversion
+    Lua.alternative e x y
 
 -- | Convert the object at the top of the stack into a string and throw
 -- it as a HsLua @'Exception'@.
diff --git a/test/Foreign/Lua/CoreTests.hs b/test/Foreign/Lua/CoreTests.hs
--- a/test/Foreign/Lua/CoreTests.hs
+++ b/test/Foreign/Lua/CoreTests.hs
@@ -76,7 +76,7 @@
     ]
 
   , testGroup "insert"
-    [ "inserts stack elements using negative indices" ?: do
+    [ "inserts stack elements using positive indices" ?: do
         pushLuaExpr "1, 2, 3, 4, 5, 6, 7, 8, 9"
         insert (-6)
         movedEl <- peek (-6) :: Lua Lua.Integer
@@ -210,10 +210,14 @@
       luaSt' <- peek stackTop
       return (luaSt == luaSt')
 
-  , "different threads are not equal in Haskell" ?: do
-      luaSt1 <- liftIO newstate
-      luaSt2 <- liftIO newstate
-      return (luaSt1 /= luaSt2)
+  , "different threads are not equal in Haskell" ?:
+    liftIO
+      (do luaSt1 <- newstate
+          luaSt2 <- newstate
+          let result = luaSt1 /= luaSt2
+          close luaSt1
+          close luaSt2
+          return result)
 
   , testGroup "thread status"
     [ "OK is base thread status" =:
diff --git a/test/Foreign/Lua/TypesTests.hs b/test/Foreign/Lua/TypesTests.hs
--- a/test/Foreign/Lua/TypesTests.hs
+++ b/test/Foreign/Lua/TypesTests.hs
@@ -169,3 +169,5 @@
   assert $ stackSize == newStackSize
   -- Check that we were able to peek at all pushed elements
   forM_ vals $ assert . (== t)
+  -- Cleanup
+  QCMonadic.run (close l)
diff --git a/test/test-hslua.hs b/test/test-hslua.hs
--- a/test/test-hslua.hs
+++ b/test/test-hslua.hs
@@ -44,7 +44,7 @@
   , Foreign.Lua.PushTests.tests
   , Foreign.Lua.FunctionCallingTests.tests
   , Foreign.Lua.UtilTests.tests
-  , testGroup "Sendings and receiving values from the stack"
+  , testGroup "Sending and receiving values from the stack"
     [ Foreign.Lua.TypesTests.tests
     , Foreign.Lua.Types.PeekableTests.tests
     , Foreign.Lua.Types.PushableTests.tests