diff --git a/dahdit-midi.cabal b/dahdit-midi.cabal
--- a/dahdit-midi.cabal
+++ b/dahdit-midi.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           dahdit-midi
-version:        0.5.4
+version:        0.5.5
 synopsis:       MIDI and OSC parsing/printing with dahdit
 description:    Please see the README on GitHub at <https://github.com/ejconlon/dahdit#readme>
 homepage:       https://github.com/ejconlon/dahdit#readme
diff --git a/src/Dahdit/Midi/Osc.hs b/src/Dahdit/Midi/Osc.hs
--- a/src/Dahdit/Midi/Osc.hs
+++ b/src/Dahdit/Midi/Osc.hs
@@ -165,6 +165,9 @@
 class IsDatum a where
   toDatum :: a -> Datum
 
+instance IsDatum Datum where
+  toDatum = id
+
 instance IsDatum Int32 where
   toDatum = DatumInt32