diff --git a/lib/Polysemy/Time/At.hs b/lib/Polysemy/Time/At.hs
--- a/lib/Polysemy/Time/At.hs
+++ b/lib/Polysemy/Time/At.hs
@@ -50,7 +50,7 @@
 
 -- |Interpret 'Time' so that the time when the program starts is @startAt@.
 interpretTimeAt ::
-  ∀ (diff :: *) t d r a .
+  ∀ (diff :: Type) t d r a .
   TimeUnit diff =>
   Torsor t diff =>
   HasDate t d =>
diff --git a/lib/Polysemy/Time/Calendar.hs b/lib/Polysemy/Time/Calendar.hs
--- a/lib/Polysemy/Time/Calendar.hs
+++ b/lib/Polysemy/Time/Calendar.hs
@@ -50,8 +50,8 @@
 
 -- |Construct datetimes, dates or times from integers.
 class Calendar dt where
-  type CalendarDate dt :: *
-  type CalendarTime dt :: *
+  type CalendarDate dt :: Type
+  type CalendarTime dt :: Type
   mkDate :: Int64 -> Int64 -> Int64 -> CalendarDate dt
   mkTime :: Int64 -> Int64 -> Int64 -> CalendarTime dt
   mkDatetime :: Int64 -> Int64 -> Int64 -> Int64 -> Int64 -> Int64 -> dt
diff --git a/lib/Polysemy/Time/Data/Time.hs b/lib/Polysemy/Time/Data/Time.hs
--- a/lib/Polysemy/Time/Data/Time.hs
+++ b/lib/Polysemy/Time/Data/Time.hs
@@ -3,7 +3,7 @@
 import Polysemy.Time.Data.TimeUnit (AddTimeUnit, TimeUnit)
 
 -- |The Time effect.
-data Time (time :: *) (date :: *) :: Effect where
+data Time (time :: Type) (date :: Type) :: Effect where
   -- |Produce the current time, possibly relative to what was set with 'SetTime' or 'SetDate'
   Now :: Time t d m t
   -- |Produce the current date, possibly relative to what was set with 'SetTime' or 'SetDate'
diff --git a/lib/Polysemy/Time/Prelude.hs b/lib/Polysemy/Time/Prelude.hs
--- a/lib/Polysemy/Time/Prelude.hs
+++ b/lib/Polysemy/Time/Prelude.hs
@@ -8,6 +8,7 @@
   module Data.Default,
   module Data.Either.Combinators,
   module Data.Foldable,
+  module Data.Kind,
   module Data.List.NonEmpty,
   module Data.Map.Strict,
   module GHC.Err,
@@ -16,7 +17,6 @@
   module Polysemy.AtomicState,
   module Polysemy.Time.Debug,
   module Polysemy.Error,
-  module Polysemy.Internal.Bundle,
   module Polysemy.Reader,
   module Polysemy.State,
   module Relude,
@@ -24,13 +24,14 @@
 
 import Control.Exception (throwIO, try)
 import qualified Data.Aeson as Aeson
-import Data.Aeson (FromJSON(parseJSON), ToJSON(toJSON))
+import Data.Aeson (FromJSON (parseJSON), ToJSON (toJSON))
 import Data.Aeson.TH (deriveFromJSON, deriveJSON)
 import Data.Composition ((.:), (.:.), (.::))
-import Data.Default (Default(def))
+import Data.Default (Default (def))
 import Data.Either.Combinators (mapLeft)
 import Data.Fixed (div')
 import Data.Foldable (foldl, traverse_)
+import Data.Kind (Type)
 import Data.List.NonEmpty ((<|))
 import qualified Data.Map.Strict as Map
 import Data.Map.Strict (Map, lookup)
@@ -62,10 +63,8 @@
   )
 import Polysemy.AtomicState (AtomicState, atomicGet, atomicGets, atomicModify', atomicPut, runAtomicStateTVar)
 import Polysemy.Error (Error, fromEither, mapError, note, runError, throw)
-import Polysemy.Internal.Bundle (Append)
 import Polysemy.Reader (Reader)
 import Polysemy.State (State, evalState, get, gets, modify, modify', put, runState)
-import Polysemy.Time.Debug (dbg, dbgs, dbgs_)
 import Relude hiding (
   Reader,
   State,
@@ -91,6 +90,8 @@
   )
 import System.IO.Error (userError)
 
+import Polysemy.Time.Debug (dbg, dbgs, dbgs_)
+
 unit ::
   Applicative f =>
   f ()
@@ -212,26 +213,23 @@
 type Basic a =
   (Eq a, Show a)
 
-type family Basics (as :: [*]) :: Constraint where
+type family Basics (as :: [Type]) :: Constraint where
   Basics '[] = ()
   Basics (a : as) = (Basic a, Basics as)
 
 type Eso a =
   (Basic a, Ord a)
 
-type family Esos (as :: [*]) :: Constraint where
+type family Esos (as :: [Type]) :: Constraint where
   Esos '[] = ()
   Esos (a : as) = (Eso a, Esos as)
 
 type Json a =
   (FromJSON a, ToJSON a, Basic a)
 
-type family Jsons (r :: [*]) :: Constraint where
+type family Jsons (r :: [Type]) :: Constraint where
   Jsons '[] = ()
   Jsons (a ': r) = (Json a, Jsons r)
-
-type a ++ b =
-  Append a b
 
 rightOr :: (a -> b) -> Either a b -> b
 rightOr f =
diff --git a/polysemy-time.cabal b/polysemy-time.cabal
--- a/polysemy-time.cabal
+++ b/polysemy-time.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           polysemy-time
-version:        0.1.2.3
+version:        0.1.2.4
 synopsis:       Polysemy Effect for Time
 description:    Please see the readme on Github at <https://github.com/tek/polysemy-time>
 category:       Time
diff --git a/readme.md b/readme.md
--- a/readme.md
+++ b/readme.md
@@ -43,7 +43,7 @@
 The only effect contained in **polysemy-time** is:
 
 ```haskell
-data Time (time :: *) (date :: *) :: Effect where
+data Time (time :: Type) (date :: Type) :: Effect where
   Now :: Time t d m t
   Today :: Time t d m d
   Sleep :: TimeUnit u => u -> Time t d m ()