diff --git a/Pandora/IO.hs b/Pandora/IO.hs
--- a/Pandora/IO.hs
+++ b/Pandora/IO.hs
@@ -5,6 +5,7 @@
 
 import "pandora" Pandora.Pattern.Morphism.Straight (Straight (Straight))
 import "pandora" Pandora.Pattern.Semigroupoid ((.))
+import "pandora" Pandora.Pattern.Category ((<--))
 import "pandora" Pandora.Pattern.Functor.Covariant (Covariant ((<-|-)))
 import "pandora" Pandora.Pattern.Functor.Semimonoidal (Semimonoidal (mult))
 import "pandora" Pandora.Pattern.Functor.Monoidal (Monoidal (unit))
@@ -14,7 +15,7 @@
 import "pandora" Pandora.Paradigm.Primary.Algebraic.Product ((:*:) ((:*:)))
 import "pandora" Pandora.Paradigm.Primary.Algebraic.One (One (One))
 import "pandora" Pandora.Paradigm.Primary.Algebraic ()
-import "pandora" Pandora.Paradigm.Controlflow.Effect.Interpreted (run, (!))
+import "pandora" Pandora.Paradigm.Controlflow.Effect.Interpreted (run, (<~))
 
 import "ghc-prim" GHC.Prim (State#, RealWorld)
 import "ghc-prim" GHC.Types (IO (IO))
@@ -23,10 +24,10 @@
 	f <-|- x = bindIO x (returnIO . f)
 
 instance Semimonoidal (-->) (:*:) (:*:) IO where
-	mult = Straight ! \(x :*: y) -> bindIO x (\x' -> bindIO y (\y' -> returnIO (x' :*: y')))
+	mult = Straight <-- \(x :*: y) -> bindIO x (\x' -> bindIO y (\y' -> returnIO (x' :*: y')))
 
 instance Monoidal (-->) (-->) (:*:) (:*:) IO where
-	unit _ = Straight ! returnIO . (! One) . run
+	unit _ = Straight <-- returnIO . (<~ One)
 
 instance Bindable (->) IO where
 	f =<< x = bindIO x f
diff --git a/pandora-io.cabal b/pandora-io.cabal
--- a/pandora-io.cabal
+++ b/pandora-io.cabal
@@ -1,5 +1,5 @@
 name:                pandora-io
-version:             0.4.9
+version:             0.5.2
 synopsis:            ...
 description:         ...
 homepage:            https://github.com/iokasimov/pandora-io
@@ -18,7 +18,7 @@
   location: https://github.com/iokasimov/pandora-io.git
 
 library
-  build-depends: ghc-prim == 0.6.1, pandora >= 0.4.9
+  build-depends: ghc-prim == 0.6.1, pandora >= 0.5.2
   exposed-modules: Pandora.IO, Pandora.IO.ASCII, Pandora.IO.Bytes
   default-language: Haskell2010
   default-extensions: