diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Revision history for effectful-st
 
+## 0.0.0.1 -- 2022-09-12
+
+* Add `:>` instance for `STE`. (Helps type inference.)
+
 ## 0.0.0.0 -- 2022-09-06
 
 * First version. Released on an unsuspecting world.
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # `effectful-st`
 
-Version 0.0.0.0
+Version 0.0.0.1
 
 ## Description
 
diff --git a/effectful-st.cabal b/effectful-st.cabal
--- a/effectful-st.cabal
+++ b/effectful-st.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               effectful-st
-version:            0.0.0.0
+version:            0.0.0.1
 license:            CC0-1.0
 license-file:       CC0-1.0.txt
 author:             Russell Hernandez Ruiz
@@ -34,7 +34,7 @@
 source-repository this
   type:     git
   location: https://git.sr.ht/~qrpnxz/effectful-st
-  tag:      0.0.0.0
+  tag:      0.0.0.1
 
 library
   hs-source-dirs:   src
diff --git a/src/Effectful/ST.hs b/src/Effectful/ST.hs
--- a/src/Effectful/ST.hs
+++ b/src/Effectful/ST.hs
@@ -9,6 +9,8 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
 {-|
 This modules provides the `STE` effect; a way to run
 the effect purely, with `Prim`, or with `IOE`; and
@@ -48,6 +50,7 @@
       SideEffects(NoSideEffects),
       StaticRep )
 import Effectful.Prim ( Prim )
+import Effectful.Internal.Effect ( type (:>)(..) )
 
 import Control.Monad.Primitive
     ( PrimBase(..), PrimMonad(PrimState) )
@@ -56,6 +59,9 @@
 -- ^ An effect for delimited primitive state-transformer actions.
 type instance DispatchOf (STE s) = Static NoSideEffects
 data instance StaticRep (STE s) = STERep
+
+instance {-# INCOHERENT #-} s1 ~ s2 => STE s1 :> (STE s2 : es) where
+  reifyIndex = 0
 
 -- | Run an 'Eff' computation with primitive state-transformer actions purely.
 runSTE :: (forall s. Eff (STE s : es) a) -> Eff es a