diff --git a/ipython-kernel/src/IHaskell/IPython/ZeroMQ.hs b/ipython-kernel/src/IHaskell/IPython/ZeroMQ.hs
index 5b2d9e16..916b8d7f 100644
--- a/ipython-kernel/src/IHaskell/IPython/ZeroMQ.hs
+++ b/ipython-kernel/src/IHaskell/IPython/ZeroMQ.hs
@@ -344,6 +344,6 @@ sendMessage debug hmackey sock msg = do
     hdr = header msg
     parentHeaderStr = maybe "{}" encodeStrict $ mhParentHeader hdr
     idents = mhIdentifiers hdr
-    metadata = "{}"
+    metadata = let Metadata mdobject = mhMetadata hdr in encodeStrict mdobject
     content = encodeStrict msg
     headStr = encodeStrict hdr