diff --git a/drama.cabal b/drama.cabal
--- a/drama.cabal
+++ b/drama.cabal
@@ -1,7 +1,7 @@
 cabal-version: 3.0
 
 name:        drama
-version:     0.1.0.0
+version:     0.1.0.1
 synopsis:    Simple actor library for Haskell
 description: Simple actor library for Haskell
 category:    Concurrency
@@ -10,6 +10,7 @@
 homepage:    https://github.com/evanrelf/drama
 license:     BSD-3-Clause
 copyright:   2021 Evan Relf
+tested-with: GHC == 8.6.5, GHC == 8.10.3
 
 
 common common
@@ -33,7 +34,7 @@
   hs-source-dirs: src
   build-depends:
     , ki           ^>= 0.2.0.1
-    , transformers ^>= 0.5.6.2
+    , transformers >= 0.5.6.2 && < 1.0
     , unagi-chan   ^>= 0.4.1.3
   exposed-modules:
     , Drama
diff --git a/src/Drama/Internal.hs b/src/Drama/Internal.hs
--- a/src/Drama/Internal.hs
+++ b/src/Drama/Internal.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE LambdaCase #-}
@@ -24,7 +25,15 @@
 import qualified Control.Concurrent.Chan.Unagi as Unagi
 import qualified Ki
 
+-- Support `MonadFail` on GHC 8.6.5
+#if MIN_VERSION_base(4,9,0)
+import Control.Monad.Fail (MonadFail)
+#endif
+#if MIN_VERSION_base(4,13,0)
+import Prelude hiding (MonadFail)
+#endif
 
+
 -- | The `Actor` monad, where you can `spawn` other actors, and `send` and
 -- `receive` messages.
 --
@@ -36,7 +45,9 @@
     , Monad
     , MonadIO
     , Alternative
+#if MIN_VERSION_base(4,9,0)
     , MonadPlus
+#endif
     , MonadFail
     , MonadFix
     )