diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,18 @@
+# 0.6.0.0
+
+* Changed type of `runEff` to match `runEff_`
+
+# 0.5.100.0
+
 * Add exports for change to "capability" nomenclature
 
 # 0.5.1.0
 
 * Add `<:` type synonym for `:>`
+
+# 0.6.0.0
+
+* Changed type of `runEff` to match `runEff_`
 
 # 0.5.0.0
 
diff --git a/bluefin-internal.cabal b/bluefin-internal.cabal
--- a/bluefin-internal.cabal
+++ b/bluefin-internal.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               bluefin-internal
-version:            0.5.100.0
+version:            0.6.0.0
 license:            MIT
 license-file:       LICENSE
 author:             Tom Ellis
diff --git a/src/Bluefin/Internal.hs b/src/Bluefin/Internal.hs
--- a/src/Bluefin/Internal.hs
+++ b/src/Bluefin/Internal.hs
@@ -238,7 +238,7 @@
 -- | Run `MonadIO` operations in 'Eff'.
 --
 -- @
--- >>> runEff_ $ \\io -> withMonadIO io $ liftIO $ do
+-- >>> runEff $ \\io -> withMonadIO io $ liftIO $ do
 --       putStrLn "Hello world!"
 -- Hello, world!
 -- @
@@ -277,7 +277,7 @@
 
 -- | Run an 'Eff' that doesn't contain any unhandled effects.
 runPureEff :: (forall es. Eff es a) -> a
-runPureEff e = unsafePerformIO (runEff_ (\_ -> e))
+runPureEff e = unsafePerformIO (runEff (\_ -> e))
 
 unsafeCoerceEff :: Eff t r -> Eff t' r
 unsafeCoerceEff = coerce
@@ -799,7 +799,7 @@
 -- due to pure exceptions being imprecise.
 --
 -- f :: IO (Either Ex1 (Either Ex2 a))
--- f = runEff_ $ \io -> do
+-- f = runEff $ \io -> do
 --   try $ \e1 -> do
 --     try $ \e2 -> do
 --       rethrowIO io e1 $ do
@@ -1481,7 +1481,7 @@
 -- | Run an 'IO' operation in 'Eff'
 --
 -- @
--- >>> runEff_ $ \\io -> do
+-- >>> runEff $ \\io -> do
 --       effIO io (putStrLn "Hello world!")
 -- Hello, world!
 -- @
@@ -1496,18 +1496,15 @@
 -- | Run an 'Eff' whose only unhandled effect is 'IO'.
 --
 -- @
--- >>> runEff_ $ \\io -> do
+-- >>> runEff $ \\io -> do
 --       effIO io (putStrLn "Hello world!")
 -- Hello, world!
 -- @
---
--- We suggest you use 'runEff_' instead, as it probably has better
--- type inference properties.
 runEff ::
-  (forall e es. IOE e -> Eff (e :& es) a) ->
+  (forall e. IOE e -> Eff e a) ->
   -- | ͘
   IO a
-runEff eff = runEff_ (makeOp . eff)
+runEff eff = runEff_ eff
 
 -- | Run an 'Eff' whose only unhandled effect is 'IO'.
 --
@@ -1517,8 +1514,8 @@
 -- Hello, world!
 -- @
 --
--- This probably has better type inference properties than 'runEff'
--- and so will probably replace it in a later version.
+-- Use 'runEff' instead.  @runEff_@ will be deprecated in a future
+-- version.
 runEff_ ::
   (forall e. IOE e -> Eff e a) ->
   -- | ͘
diff --git a/src/Bluefin/Internal/Examples.hs b/src/Bluefin/Internal/Examples.hs
--- a/src/Bluefin/Internal/Examples.hs
+++ b/src/Bluefin/Internal/Examples.hs
@@ -35,7 +35,7 @@
 import Prelude qualified
 
 monadIOExample :: IO ()
-monadIOExample = runEff_ $ \io -> withMonadIO io $ liftIO $ do
+monadIOExample = runEff $ \io -> withMonadIO io $ liftIO $ do
   name <- readLn
   putStrLn ("Hello " ++ name)
 
@@ -133,7 +133,7 @@
   pure "End of loop"
 
 effIOExample :: IO ()
-effIOExample = runEff_ $ \io -> do
+effIOExample = runEff $ \io -> do
   effIO io (putStrLn "Hello world!")
 
 example1_ :: (Int, Int)
@@ -181,7 +181,7 @@
 -- Count non-empty lines from stdin, and print a friendly message,
 -- until we see "STOP".
 example3_ :: IO ()
-example3_ = runEff_ $ \io -> do
+example3_ = runEff $ \io -> do
   let getLineUntilStop y = withJump $ \stop -> forever $ do
         line <- effIO io getLine
         when (line == "STOP") $
@@ -272,12 +272,12 @@
           useImplUnder . x
 
 awaitExample :: IO ()
-awaitExample = runEff_ $ \io -> do
+awaitExample = runEff $ \io -> do
   awaitList [1 :: Int ..] io $ awaitUsage io $ \rec -> do
     replicateM_ 5 (await rec)
 
 consumeStreamExample :: IO (Either String String)
-consumeStreamExample = runEff_ $ \io -> do
+consumeStreamExample = runEff $ \io -> do
   try $ \ex -> do
     consumeStream
       ( \r ->
@@ -309,7 +309,7 @@
       )
 
 consumeStreamExample2 :: IO ()
-consumeStreamExample2 = runEff_ $ \io -> do
+consumeStreamExample2 = runEff $ \io -> do
   let counter yeven yodd = for_ [0 :: Int .. 10] $ \i -> do
         if even i
           then yield yeven i
@@ -334,7 +334,7 @@
   bar
 
 connectExample :: IO (Either String String)
-connectExample = runEff_ $ \io -> do
+connectExample = runEff $ \io -> do
   try $ \ex -> do
     connectCoroutines
       ( \y -> bracket
@@ -367,7 +367,7 @@
       )
 
 zipCoroutinesExample :: IO ()
-zipCoroutinesExample = runEff_ $ \io -> do
+zipCoroutinesExample = runEff $ \io -> do
   let m1 y = do
         r <- yieldCoroutine y 1
         evalModify r $ \rs -> do
@@ -447,7 +447,7 @@
   myBail h
 
 countExample :: IO ()
-countExample = runEff_ $ \io -> do
+countExample = runEff $ \io -> do
   evalModify @Int 0 $ \sn -> do
     withJump $ \break -> forever $ do
       n <- get sn
@@ -505,7 +505,7 @@
     modify state (+ i)
 
 runIncrementReadLine :: IO (Either String Int)
-runIncrementReadLine = runEff_ $ \io -> do
+runIncrementReadLine = runEff $ \io -> do
   try $ \exception -> do
     ((), r) <- runModify 0 $ \state -> do
       incrementReadLine state exception io
@@ -607,7 +607,7 @@
 runCounter3B io k = useImplIn k (MkCounter3B (mapHandle io))
 
 exampleCounter3B :: IO ()
-exampleCounter3B = runEff_ $ \io -> runCounter3B io $ \c -> do
+exampleCounter3B = runEff $ \io -> runCounter3B io $ \c -> do
   incCounter3B c
   incCounter3B c
   incCounter3B c
@@ -936,7 +936,7 @@
 -- Left "File not found: /tmp/doesn't exist"
 
 exampleRunFileSystemIO :: IO (Either String String)
-exampleRunFileSystemIO = runEff_ $ \io -> try $ \ex ->
+exampleRunFileSystemIO = runEff $ \io -> try $ \ex ->
   runFileSystemIO ex io action
 
 -- > exampleRunFileSystemIO
@@ -988,13 +988,13 @@
     pure st
 
 pipesExample1 :: IO ()
-pipesExample1 = runEff_ $ \io -> runEffect (count >-> P.print io)
+pipesExample1 = runEff $ \io -> runEffect (count >-> P.print io)
   where
     count :: (e <: es) => Producer Int e -> Eff es ()
     count p = for_ [1 .. 5] $ \i -> P.yield p i
 
 pipesExample2 :: IO String
-pipesExample2 = runEff_ $ \io -> runEffect $ do
+pipesExample2 = runEff $ \io -> runEffect $ do
   stdinLn io >-> takeWhile' (/= "quit") >-> stdoutLn io
 
 -- Acquiring resource
@@ -1006,7 +1006,7 @@
 -- Releasing resource
 -- Finishing
 promptCoroutine :: IO ()
-promptCoroutine = runEff_ $ \io -> do
+promptCoroutine = runEff $ \io -> do
   -- consumeStream connects a consumer to a producer
   consumeStream
     -- Like a pipes Consumer.  Prints the first five elements it
@@ -1027,7 +1027,7 @@
   effIO io (putStrLn "Finishing")
 
 rethrowIOExample :: IO ()
-rethrowIOExample = runEff_ $ \io -> do
+rethrowIOExample = runEff $ \io -> do
   r <- try $ \ex -> do
     rethrowIO @Control.Exception.IOException io ex $ do
       effIO io (Prelude.readFile "/tmp/doesnt-exist")
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -11,7 +11,7 @@
 import Prelude hiding (break, read)
 
 main :: IO ()
-main = runEff_ $ \io -> do
+main = runEff $ \io -> do
   runSpecH io $ \y -> do
     let assertEqual' = assertEqual y