diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 283f81810..a622dddba 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -5003,9 +5003,9 @@ UniValue z_sendmany(const UniValue& params, bool fHelp, const CPubKey& mypk)
     if (!EnsureWalletIsAvailable(fHelp))
         return NullUniValue;
 
-    if (fHelp || params.size() < 2 || params.size() > 4)
+    if (fHelp || params.size() < 2 || params.size() > 5)
         throw runtime_error(
-            "z_sendmany \"fromaddress\" [{\"address\":... ,\"amount\":...},...] ( minconf ) ( fee )\n"
+            "z_sendmany \"fromaddress\" [{\"address\":... ,\"amount\":...},...] ( minconf ) ( fee ) (opreturn)\n"
             "\nSend multiple times. Amounts are decimal numbers with at most 8 digits of precision."
             "\nChange generated from a taddr flows to a new taddr address, while change generated from a zaddr returns to itself."
             "\nWhen sending coinbase UTXOs to a zaddr, change is not allowed. The entire value of the UTXO(s) must be consumed."