diff --git a/qa/rpc-tests/test_framework/mininode.py b/qa/rpc-tests/test_framework/mininode.py
index 359553def..5a7dc067a 100755
--- a/qa/rpc-tests/test_framework/mininode.py
+++ b/qa/rpc-tests/test_framework/mininode.py
@@ -58,6 +58,7 @@ OVERWINTER_BRANCH_ID = 0x5BA81B19
 SAPLING_BRANCH_ID = 0x76B809BB
 BLOSSOM_BRANCH_ID = 0x2BB40E60
 HEARTWOOD_BRANCH_ID = 0xF5B9230B
+NU4_BRANCH_ID = 0xE9FF75A6
 
 MAX_INV_SZ = 50000
 
diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 31a9673ff..0317cf6d8 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -122,6 +122,9 @@ public:
         consensus.vUpgrades[Consensus::UPGRADE_HEARTWOOD].nProtocolVersion = 170011;
         consensus.vUpgrades[Consensus::UPGRADE_HEARTWOOD].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
+        consensus.vUpgrades[Consensus::UPGRADE_NU4].nProtocolVersion = 170013;
+        consensus.vUpgrades[Consensus::UPGRADE_NU4].nActivationHeight =
+            Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 
         // The best chain should have at least this much work.
         consensus.nMinimumChainWork = uint256S("000000000000000000000000000000000000000000000000017e73a331fae01c");
@@ -322,6 +325,9 @@ public:
             uint256S("00367515ef2e781b8c9358b443b6329572599edd02c59e8af67db9785122f298");
         consensus.vUpgrades[Consensus::UPGRADE_HEARTWOOD].nProtocolVersion = 170010;
         consensus.vUpgrades[Consensus::UPGRADE_HEARTWOOD].nActivationHeight = 903800;
+        consensus.vUpgrades[Consensus::UPGRADE_NU4].nProtocolVersion = 170012;
+        consensus.vUpgrades[Consensus::UPGRADE_NU4].nActivationHeight =
+            Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 
         // On testnet we activate this rule 6 blocks after Blossom activation. From block 299188 and
         // prior to Blossom activation, the testnet minimum-difficulty threshold was 15 minutes (i.e.
@@ -479,6 +485,9 @@ public:
         consensus.vUpgrades[Consensus::UPGRADE_HEARTWOOD].nProtocolVersion = 170010;
         consensus.vUpgrades[Consensus::UPGRADE_HEARTWOOD].nActivationHeight =
             Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
+        consensus.vUpgrades[Consensus::UPGRADE_NU4].nProtocolVersion = 170012;
+        consensus.vUpgrades[Consensus::UPGRADE_NU4].nActivationHeight =
+            Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT;
 
         // The best chain should have at least this much work.
         consensus.nMinimumChainWork = uint256S("0x00");
diff --git a/src/consensus/params.h b/src/consensus/params.h
index 78e5e5c5a..3ccb2e109 100644
--- a/src/consensus/params.h
+++ b/src/consensus/params.h
@@ -28,6 +28,7 @@ enum UpgradeIndex : uint32_t {
     UPGRADE_SAPLING,
     UPGRADE_BLOSSOM,
     UPGRADE_HEARTWOOD,
+    UPGRADE_NU4,
     // NOTE: Also add new upgrades to NetworkUpgradeInfo in upgrades.cpp
     MAX_NETWORK_UPGRADES
 };
diff --git a/src/consensus/upgrades.cpp b/src/consensus/upgrades.cpp
index 03b2d6df6..798480f3d 100644
--- a/src/consensus/upgrades.cpp
+++ b/src/consensus/upgrades.cpp
@@ -22,22 +22,27 @@ const struct NUInfo NetworkUpgradeInfo[Consensus::MAX_NETWORK_UPGRADES] = {
     {
         /*.nBranchId =*/ 0x5ba81b19,
         /*.strName =*/ "Overwinter",
-        /*.strInfo =*/ "See https://z.cash/upgrade/overwinter.html for details.",
+        /*.strInfo =*/ "See https://z.cash/upgrade/overwinter/ for details.",
     },
     {
         /*.nBranchId =*/ 0x76b809bb,
         /*.strName =*/ "Sapling",
-        /*.strInfo =*/ "See https://z.cash/upgrade/sapling.html for details.",
+        /*.strInfo =*/ "See https://z.cash/upgrade/sapling/ for details.",
     },
     {
         /*.nBranchId =*/ 0x2bb40e60,
         /*.strName =*/ "Blossom",
-        /*.strInfo =*/ "See https://z.cash/upgrade/blossom.html for details.",
+        /*.strInfo =*/ "See https://z.cash/upgrade/blossom/ for details.",
     },
     {
         /*.nBranchId =*/ 0xf5b9230b,
         /*.strName =*/ "Heartwood",
         /*.strInfo =*/ "See https://z.cash/upgrade/heartwood/ for details.",
+    },
+    {
+        /*.nBranchId =*/ 0xe9ff75a6,
+        /*.strName =*/ "NU4",
+        /*.strInfo =*/ "See https://z.cash/upgrade/nu4/ for details.",
     }
 };
 
diff --git a/src/utiltest.cpp b/src/utiltest.cpp
index c8e01fad5..5e74704a0 100644
--- a/src/utiltest.cpp
+++ b/src/utiltest.cpp
@@ -251,6 +251,29 @@ void RegtestDeactivateHeartwood() {
     SelectParams(CBaseChainParams::MAIN);
 }
 
+const Consensus::Params& RegtestActivateNU4(bool updatePow, int nu4ActivationHeight) {
+    SelectParams(CBaseChainParams::REGTEST);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_OVERWINTER, Consensus::NetworkUpgrade::ALWAYS_ACTIVE);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_SAPLING, Consensus::NetworkUpgrade::ALWAYS_ACTIVE);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_BLOSSOM, Consensus::NetworkUpgrade::ALWAYS_ACTIVE);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_HEARTWOOD, Consensus::NetworkUpgrade::ALWAYS_ACTIVE);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_NU4, nu4ActivationHeight);
+    if (updatePow) {
+        UpdateRegtestPow(32, 16, uint256S("0007ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"));
+    }
+    return Params().GetConsensus();
+}
+
+void RegtestDeactivateNU4() {
+    UpdateRegtestPow(0, 0, uint256S("0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f"));
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_NU4, Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_HEARTWOOD, Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_BLOSSOM, Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_SAPLING, Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_OVERWINTER, Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT);
+    SelectParams(CBaseChainParams::MAIN);
+}
+
 
 libzcash::SaplingExtendedSpendingKey GetTestMasterSaplingSpendingKey() {
     std::vector<unsigned char, secure_allocator<unsigned char>> rawSeed(32);
diff --git a/src/utiltest.h b/src/utiltest.h
index 07409b786..056b3aa46 100644
--- a/src/utiltest.h
+++ b/src/utiltest.h
@@ -53,6 +53,10 @@ const Consensus::Params& RegtestActivateHeartwood(bool updatePow, int heartwoodA
 
 void RegtestDeactivateHeartwood();
 
+const Consensus::Params& RegtestActivateNU4(bool updatePow, int nu4ActivationHeight = Consensus::NetworkUpgrade::ALWAYS_ACTIVE);
+
+void RegtestDeactivateNU4();
+
 libzcash::SaplingExtendedSpendingKey GetTestMasterSaplingSpendingKey();
 
 CKey AddTestCKeyToKeyStore(CBasicKeyStore& keyStore);