diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 801b2d574..9023b80f6 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -3485,12 +3485,13 @@ UniValue z_getoperationstatus_IMPL(const UniValue& params, bool fRemoveFinishedO
 }
 
 
+// JSDescription size depends on the transaction version
+#define V3_JS_DESCRIPTION_SIZE    (GetSerializeSize(JSDescription(), SER_NETWORK, (OVERWINTER_TX_VERSION | (1 << 31))))
 // Here we define the maximum number of zaddr outputs that can be included in a transaction.
 // If input notes are small, we might actually require more than one joinsplit per zaddr output.
 // For now though, we assume we use one joinsplit per zaddr output (and the second output note is change).
 // We reduce the result by 1 to ensure there is room for non-joinsplit CTransaction data.
-#define Z_SENDMANY_MAX_ZADDR_OUTPUTS_BEFORE_SAPLING    ((MAX_TX_SIZE_BEFORE_SAPLING / GetSerializeSize(JSDescription(), SER_NETWORK, PROTOCOL_VERSION)) - 1)
-#define Z_SENDMANY_MAX_ZADDR_OUTPUTS    ((MAX_TX_SIZE_AFTER_SAPLING / GetSerializeSize(JSDescription(), SER_NETWORK, PROTOCOL_VERSION)) - 1)
+#define Z_SENDMANY_MAX_ZADDR_OUTPUTS_BEFORE_SAPLING    ((MAX_TX_SIZE_BEFORE_SAPLING / V3_JS_DESCRIPTION_SIZE) - 1)
 
 // transaction.h comment: spending taddr output requires CTxIn >= 148 bytes and typical taddr txout is 34 bytes
 #define CTXIN_SPEND_DUST_SIZE   148
@@ -3507,7 +3508,7 @@ UniValue z_sendmany(const UniValue& params, bool fHelp)
             "\nSend multiple times. Amounts are double-precision floating point numbers."
             "\nChange from a taddr flows to a new taddr address, while change from 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."
-            + strprintf("\nCurrently, the maximum number of zaddr outputs is %d due to transaction size limits.\n", Z_SENDMANY_MAX_ZADDR_OUTPUTS)
+            + strprintf("\nBefore Sapling activates, the maximum number of zaddr outputs is %d due to transaction size limits.\n", Z_SENDMANY_MAX_ZADDR_OUTPUTS_BEFORE_SAPLING)
             + HelpRequiringPassphrase() + "\n"
             "\nArguments:\n"
             "1. \"fromaddress\"         (string, required) The taddr or zaddr to send the funds from.\n"
@@ -3622,24 +3623,33 @@ UniValue z_sendmany(const UniValue& params, bool fHelp)
     }
 
     int nextBlockHeight = chainActive.Height() + 1;
-    size_t max_zaddr_outputs = Z_SENDMANY_MAX_ZADDR_OUTPUTS;
+    CMutableTransaction mtx;
+    mtx.fOverwintered = true;
+    mtx.nVersionGroupId = SAPLING_VERSION_GROUP_ID;
+    mtx.nVersion = SAPLING_TX_VERSION;
     unsigned int max_tx_size = MAX_TX_SIZE_AFTER_SAPLING;
     if (!NetworkUpgradeActive(nextBlockHeight, Params().GetConsensus(), Consensus::UPGRADE_SAPLING)) {
-        max_zaddr_outputs = Z_SENDMANY_MAX_ZADDR_OUTPUTS_BEFORE_SAPLING;
-        max_tx_size = MAX_TX_SIZE_BEFORE_SAPLING;
-    }
+        if (NetworkUpgradeActive(nextBlockHeight, Params().GetConsensus(), Consensus::UPGRADE_OVERWINTER)) {
+            mtx.nVersionGroupId = OVERWINTER_VERSION_GROUP_ID;
+            mtx.nVersion = OVERWINTER_TX_VERSION;
+        } else {
+            mtx.fOverwintered = false;
+            mtx.nVersion = 2;
+        }
 
-    // Check the number of zaddr outputs does not exceed the limit.
-    if (zaddrRecipients.size() > max_zaddr_outputs)  {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, too many zaddr outputs");
+        max_tx_size = MAX_TX_SIZE_BEFORE_SAPLING;
+
+        // Check the number of zaddr outputs does not exceed the limit.
+        if (zaddrRecipients.size() > Z_SENDMANY_MAX_ZADDR_OUTPUTS_BEFORE_SAPLING)  {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, too many zaddr outputs");
+        }
     }
 
     // As a sanity check, estimate and verify that the size of the transaction will be valid.
     // Depending on the input notes, the actual tx size may turn out to be larger and perhaps invalid.
     size_t txsize = 0;
-    CMutableTransaction mtx;
-    mtx.nVersion = 2;
     for (int i = 0; i < zaddrRecipients.size(); i++) {
+        // TODO Check whether the recipient is a Sprout or Sapling address
         mtx.vjoinsplit.push_back(JSDescription());
     }
     CTransaction tx(mtx);