diff --git a/lib/http/rpc.js b/lib/http/rpc.js
index a21efaec..2de21437 100644
--- a/lib/http/rpc.js
+++ b/lib/http/rpc.js
@@ -2644,7 +2644,7 @@ RPC.prototype.blockToJSON = co(function* blockToJSON(entry, block, details) {
     version: entry.version,
     versionHex: util.hex32(entry.version),
     merkleroot: util.revHex(entry.merkleRoot),
-    coinbase: block.txs[0].inputs[0].script,
+    coinbase: block.txs[0].inputs[0].script.toJSON(),
     tx: txs,
     time: entry.ts,
     mediantime: mtp,