diff --git a/src/main.cpp b/src/main.cpp
index f1b27f8ef..8b4d2feb6 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1787,7 +1787,7 @@ bool AcceptToMemoryPool(
     if (tx.IsCoinBase())
         return state.DoS(100, false, REJECT_INVALID, "coinbase");
 
-    // Rather not work on nonstandard transactions (unless -testnet/-regtest)
+    // Rather not work on nonstandard transactions (unless -regtest)
     string reason;
     if (chainparams.RequireStandard() && !IsStandardTx(tx, reason, chainparams, nextBlockHeight))
         return state.DoS(0, false, REJECT_NONSTANDARD, reason);
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
index 5f5248956..8c1872922 100644
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -59,8 +59,15 @@ bool IsStandardTx(const CTransaction& tx, std::string& reason, const CChainParam
 {
     bool overwinterActive = chainparams.GetConsensus().NetworkUpgradeActive(nHeight,  Consensus::UPGRADE_OVERWINTER);
     bool saplingActive = chainparams.GetConsensus().NetworkUpgradeActive(nHeight, Consensus::UPGRADE_SAPLING);
+    bool nu5Active = chainparams.GetConsensus().NetworkUpgradeActive(nHeight, Consensus::UPGRADE_NU5);
 
-    if (saplingActive) {
+    if (nu5Active) {
+        // NU5 standard rules apply
+        if (tx.nVersion > CTransaction::NU5_MAX_CURRENT_VERSION || tx.nVersion < CTransaction::NU5_MIN_CURRENT_VERSION) {
+            reason = "nu5-version";
+            return false;
+        }
+    } else if (saplingActive) {
         // Sapling standard rules apply
         if (tx.nVersion > CTransaction::SAPLING_MAX_CURRENT_VERSION || tx.nVersion < CTransaction::SAPLING_MIN_CURRENT_VERSION) {
             reason = "sapling-version";
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index e005cd827..b21803720 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -719,6 +719,8 @@ public:
     static const int32_t OVERWINTER_MAX_CURRENT_VERSION = 3;
     static const int32_t SAPLING_MIN_CURRENT_VERSION = 4;
     static const int32_t SAPLING_MAX_CURRENT_VERSION = 4;
+    static const int32_t NU5_MIN_CURRENT_VERSION = 4;
+    static const int32_t NU5_MAX_CURRENT_VERSION = 5;
 
     static_assert(SPROUT_MIN_CURRENT_VERSION >= SPROUT_MIN_TX_VERSION,
                   "standard rule for tx version should be consistent with network rule");
@@ -737,6 +739,13 @@ public:
                     SAPLING_MAX_CURRENT_VERSION >= SAPLING_MIN_CURRENT_VERSION),
                   "standard rule for tx version should be consistent with network rule");
 
+    static_assert(NU5_MIN_CURRENT_VERSION >= SAPLING_MIN_TX_VERSION,
+                  "standard rule for tx version should be consistent with network rule");
+
+    static_assert( (NU5_MAX_CURRENT_VERSION <= ZIP225_MAX_TX_VERSION &&
+                    NU5_MAX_CURRENT_VERSION >= NU5_MIN_CURRENT_VERSION),
+                  "standard rule for tx version should be consistent with network rule");
+
     // The local variables are made const to prevent unintended modification
     // without updating the cached hash value. However, CTransaction is not
     // actually immutable; deserialization and assignment are implemented,