diff --git a/src/routes/v3/slp.js b/src/routes/v3/slp.js
index 182296c..1f3b3b2 100644
--- a/src/routes/v3/slp.js
+++ b/src/routes/v3/slp.js
@@ -1647,7 +1647,7 @@ class Slp {
         tokenUtxos,
         sendQty
       )
-      return opReturn
+      return res.json(opReturn)
     } catch (err) {
       wlogger.error('Error in slp.js/generateSendOpReturn().', err)