diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,12 +1,8 @@
 # Revision history for eventuo11y
 
-## 0.3.2.0 -- 2022-10-04
-
-Add hoistEvent
-
-## 0.3.1.0 -- 2022-10-04
+## 0.4.0.0 -- 2022-10-04
 
-Add causedEventBackend
+Have SomeJSONException take a RenderExJSON directly
 
 ## 0.3.0.0 -- 2022-10-03
 
diff --git a/Example.hs b/Example.hs
--- a/Example.hs
+++ b/Example.hs
@@ -15,7 +15,7 @@
 import Data.Void
 import Foreign.C.Error
 import Foreign.C.Types
-import Foreign.ForeignPtr.Safe
+import Foreign.ForeignPtr
 import Foreign.Ptr
 import GHC.Generics
 import Observe.Event
@@ -99,7 +99,7 @@
 
 -- Our exception is beneath SomeJSONException in the hierarchy
 instance Exception BadOpen where
-  toException = jsonExceptionToException
+  toException = jsonExceptionToException toJSON
   fromException = jsonExceptionFromException
 
 -- end module File
diff --git a/eventuo11y.cabal b/eventuo11y.cabal
--- a/eventuo11y.cabal
+++ b/eventuo11y.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               eventuo11y
-version:            0.3.2.0
+version:            0.4.0.0
 synopsis:           An event-oriented observability library
 description:
   Instrument your Haskell codebase with wide, semantically meaningful events.
@@ -26,7 +26,7 @@
   See "Observe.Event.Backend" for documentation on writing an
   @EventBackend@.
 
-  See [Example.hs](https://github.com/shlevy/eventuo11y/tree/v0.3.2.0/Example.hs) for an example.
+  See [Example.hs](https://github.com/shlevy/eventuo11y/tree/v0.4.0.0/Example.hs) for an example.
 
   See [eventuo11y-batteries](https://hackage.haskell.org/package/eventuo11y-batteries) for miscellaneous
   framework-specific helpers.
@@ -58,7 +58,7 @@
     Observe.Event.Render.JSON
 
   build-depends:
-    , aeson          ^>=2.0.2.0
+    , aeson          ^>=2.0
     , base           >=4.14    && <4.17
     , bytestring     >=0.10    && <0.12
     , exceptions     ^>=0.10
diff --git a/src/Observe/Event.hs b/src/Observe/Event.hs
--- a/src/Observe/Event.hs
+++ b/src/Observe/Event.hs
@@ -40,7 +40,6 @@
 --  t'Observe.Event.Render.JSON.RenderFieldJSON' to use JSON rendering 'EventBackend's.
 module Observe.Event
   ( Event,
-    hoistEvent,
 
     -- * Event manipulation #eventmanip#
     reference,
@@ -59,7 +58,6 @@
     -- * 'EventBackend's
     EventBackend,
     subEventBackend,
-    causedEventBackend,
     unitEventBackend,
     pairEventBackend,
     hoistEventBackend,
@@ -106,15 +104,6 @@
     finishFlag :: !(OnceFlag m)
   }
 
--- | Hoist an 'Event' along a given natural transformation into a new monad.
-hoistEvent :: (Functor m, Functor n) => (forall x. m x -> n x) -> Event m r s f -> Event n r s f
-hoistEvent nt Event {..} =
-  Event
-    { backend = hoistEventBackend nt backend,
-      impl = hoistEventImpl nt impl,
-      finishFlag = hoistOnceFlag nt finishFlag
-    }
-
 -- | Obtain a reference to an 'Event'.
 --
 -- References are used to link 'Event's together, either in
@@ -334,12 +323,3 @@
   Event m r s f ->
   EventBackend m r s
 subEventBackend Event {..} = modifyEventBackend (setAncestor $ referenceImpl impl) backend
-
--- | An 'EventBackend' where every otherwise causeless event will be marked
--- as caused by the given 'Event'.
-causedEventBackend ::
-  (Monad m) =>
-  -- | The parent event.
-  Event m r s f ->
-  EventBackend m r s
-causedEventBackend Event {..} = modifyEventBackend (setInitialCause $ referenceImpl impl) backend
diff --git a/src/Observe/Event/Backend.hs b/src/Observe/Event/Backend.hs
--- a/src/Observe/Event/Backend.hs
+++ b/src/Observe/Event/Backend.hs
@@ -18,7 +18,6 @@
     unitEventBackend,
     pairEventBackend,
     hoistEventBackend,
-    hoistEventImpl,
     narrowEventBackend,
     narrowEventBackend',
 
@@ -155,21 +154,19 @@
   EventBackend n r s
 hoistEventBackend nt backend =
   EventBackend
-    { newEventImpl = nt . fmap (hoistEventImpl nt) . newEventImpl backend,
+    { newEventImpl = nt . fmap hoistEventImpl . newEventImpl backend,
       newOnceFlag = hoistOnceFlag nt <$> (nt $ newOnceFlag backend)
     }
-
--- | Hoist an 'EventImpl' along a given natural transformation into a new monad.
-hoistEventImpl :: (forall x. m x -> n x) -> EventImpl m r f -> EventImpl n r f
-hoistEventImpl nt (EventImpl {..}) =
-  EventImpl
-    { referenceImpl,
-      addFieldImpl = nt . addFieldImpl,
-      addParentImpl = nt . addParentImpl,
-      addProximateImpl = nt . addProximateImpl,
-      finalizeImpl = nt finalizeImpl,
-      failImpl = nt . failImpl
-    }
+  where
+    hoistEventImpl (EventImpl {..}) =
+      EventImpl
+        { referenceImpl,
+          addFieldImpl = nt . addFieldImpl,
+          addParentImpl = nt . addParentImpl,
+          addProximateImpl = nt . addProximateImpl,
+          finalizeImpl = nt $ finalizeImpl,
+          failImpl = nt . failImpl
+        }
 
 -- | Narrow an 'EventBackend' to a new selector type via a given injection function.
 --
diff --git a/src/Observe/Event/Render/JSON.hs b/src/Observe/Event/Render/JSON.hs
--- a/src/Observe/Event/Render/JSON.hs
+++ b/src/Observe/Event/Render/JSON.hs
@@ -64,27 +64,28 @@
 -- structured exceptions in a JSON backend, so long as you provide a
 -- 'RenderExJSON' for your base exception type.
 renderJSONException :: RenderExJSON SomeJSONException
-renderJSONException (SomeJSONException e) = toJSON e
+renderJSONException (SomeJSONException render e) = render e
 
 -- | A possible base type for structured exceptions renderable to JSON.
 --
 -- It is __not__ necessary to use 'SomeJSONException' for the base of your
 -- structured exceptions in a JSON backend, so long as you provide a
 -- 'RenderExJSON' for your base exception type.
-data SomeJSONException = forall e. (Exception e, ToJSON e) => SomeJSONException e
+data SomeJSONException
+  = forall e. Exception e => SomeJSONException (RenderExJSON e) e
 
 instance Show SomeJSONException where
-  show (SomeJSONException e) = show e
-  showsPrec i (SomeJSONException e) = showsPrec i e
+  show (SomeJSONException _ e) = show e
+  showsPrec i (SomeJSONException _ e) = showsPrec i e
 
 instance Exception SomeJSONException
 
 -- | Used to create sub-classes of 'SomeJSONException'.
-jsonExceptionToException :: (Exception e, ToJSON e) => e -> SomeException
-jsonExceptionToException = toException . SomeJSONException
+jsonExceptionToException :: (Exception e) => RenderExJSON e -> e -> SomeException
+jsonExceptionToException render = toException . SomeJSONException render
 
 -- | Used to create sub-classes of 'SomeJSONException'.
 jsonExceptionFromException :: (Exception e) => SomeException -> Maybe e
 jsonExceptionFromException x = do
-  SomeJSONException a <- fromException x
+  SomeJSONException _ a <- fromException x
   cast a