jackchuma · Sep 11, 2026 · Sep 11, 2026 · Sep 11, 2026
diff --git a/deploy-config/local.json b/deploy-config/local.json
@@ -31,6 +31,7 @@
   "operatorFeeVaultWithdrawalNetwork": 0,
   "p2pSequencerAddress": "0x9965507D1a55bcC2695C58ba16FB37d819B0A4dc",
   "proofMaturityDelaySeconds": 604800,
+  "protocolVersionsInitialMinimumVersion": "0x1000000000000000000000000",
   "proxyAdminOwner": "0x9965507D1a55bcC2695C58ba16FB37d819B0A4dc",
   "respectedGameType": 621,
   "sequencerFeeVaultMinimumWithdrawalAmount": "0x8ac7230489e80000",

diff --git a/scripts/deploy/DeployConfig.s.sol b/scripts/deploy/DeployConfig.s.sol
@@ -136,6 +136,7 @@ contract DeployConfig is Script {
 
     function _readProtocolVersionsInitialMinimumVersion(string memory _json) internal {
         uint256 minimumVersion = _json.readUintOr("$.protocolVersionsInitialMinimumVersion", 0);
+        require(minimumVersion != 0, "DeployConfig: initial minimum protocol version must be non-zero");
         require(minimumVersion <= type(uint128).max, "DeployConfig: initial minimum protocol version exceeds uint128");
         protocolVersionsInitialMinimumVersion = minimumVersion;
     }

diff --git a/scripts/libraries/DeployUtils.sol b/scripts/libraries/DeployUtils.sol
@@ -106,7 +106,7 @@ library DeployUtils {
         internal
         view
     {
-        if (_minimumProtocolVersion > type(uint128).max) {
+        if (_minimumProtocolVersion == 0 || _minimumProtocolVersion > type(uint128).max) {
             revert IProtocolVersions.ProtocolVersions_InvalidProtocolVersion();
         }
 
@@ -117,9 +117,6 @@ library DeployUtils {
         uint64 previousTimestamp;
         for (uint256 id = 0; id < _schedule.length; id++) {
             uint64 timestamp = _schedule[id];
-            if (timestamp != 0 && _minimumProtocolVersion == 0) {
-                revert IProtocolVersions.ProtocolVersions_InvalidProtocolVersion();
-            }
             if (timestamp > currentTimestamp && timestamp < minimumFutureTimestamp) {
                 revert IProtocolVersions.ProtocolVersions_InsufficientNotice(timestamp);
             }

diff --git a/scripts/libraries/Types.sol b/scripts/libraries/Types.sol
@@ -36,8 +36,7 @@ library Types {
     ///              upgrade in the node's fork order, zero for unscheduled ones. Seeds
     ///              `ProtocolVersions` at initialization, which is the only way to enter
     ///              activations that are already in the past.
-    /// @custom:field initialMinimumProtocolVersion Packed semver required by non-zero timestamps in the initial
-    /// schedule.
+    /// @custom:field initialMinimumProtocolVersion Non-zero packed semver required by nodes.
     struct DeployInput {
         Roles roles;
         uint32 basefeeScalar;

diff --git a/scripts/multiproof/README.md b/scripts/multiproof/README.md
@@ -56,7 +56,7 @@ Other relevant fields:
 | `multiproofGenesisOutputRoot`  | Initial anchor output root                                                        |
 | `multiproofGenesisBlockNumber` | Initial anchor L2 block number                                                    |
 | `protocolVersionsInitialSchedule` | Hardfork activation timestamps in the node's fork order, `0` for unscheduled forks. Omit for a chain with no history; past activations cannot be added after deployment |
-| `protocolVersionsInitialMinimumVersion` | Packed semver required by every non-zero initial schedule timestamp. Must be non-zero when the initial schedule contains an activation |
+| `protocolVersionsInitialMinimumVersion` | Non-zero packed semver required by nodes |
 
 ### Step 2: Deploy contracts
 

diff --git a/snapshots/semver-lock.json b/snapshots/semver-lock.json
@@ -16,8 +16,8 @@
     "sourceCodeHash": "0x811596e7486cab9ceeeb61405b9ae510d93fcbbdfa11949201a367506c53194a"
   },
   "src/L1/ProtocolVersions.sol:ProtocolVersions": {
-    "initCodeHash": "0x54c2a142728d60511fd15a7d6bb962b0f33d833ee727de16189fd18b6246b492",
-    "sourceCodeHash": "0x53c8ad6dc42e61b43b3ef2a91e154a02e719c595c8d1481b4b738faa7ebdf13d"
+    "initCodeHash": "0xbca4c0d69dcb7a196a9ebfcc8cb77162fa090377c5dda99831d61c6c68ba4352",
+    "sourceCodeHash": "0x411f2590b43bf6fe9d70f393c8e0349192a1aa895ec0fbe0d7695831d3b6cb94"
   },
   "src/L1/SuperchainConfig.sol:SuperchainConfig": {
     "initCodeHash": "0x9b1f3555b499709485d51d5d9665002c0eb1e5eb893be1fb978a30749e894858",

diff --git a/src/L1/ProtocolVersions.sol b/src/L1/ProtocolVersions.sol
@@ -128,16 +128,15 @@ contract ProtocolVersions is ProxyAdminOwnedBase, Initializable, Reinitializable
     ///      already has a hardfork history can be represented faithfully at deployment, while it is
     ///      still impossible for any proof game to have pinned a commitment from this registry.
     ///      Future activations must provide MIN_NOTICE, matching every post-initialization write path.
-    /// @dev Any non-zero imported timestamp requires a non-zero packed protocol version so nodes can
-    ///      validate the schedule immediately after deployment.
+    /// @dev A non-zero packed protocol version is required so nodes can validate the registry
+    ///      immediately after deployment.
     ///
     /// @param _incidentResponder Initial incidentResponder allowed to delay activations, or address(0) to leave unset.
     /// @param _initialSchedule   Activation timestamps for already-known upgrades, ordered by ascending
     ///                           upgrade id, using 0 for an upgrade that is registered but unscheduled.
     ///                           Future timestamps must be at least MIN_NOTICE from block.timestamp.
     ///                           Pass an empty array for a chain with no upgrade history.
-    /// @param _initialMinimumProtocolVersion Packed semver required by an imported activation, or 0 when
-    ///                                       the initial schedule has no non-zero timestamps.
+    /// @param _initialMinimumProtocolVersion Packed semver required by nodes. Must be non-zero and fit in 128 bits.
     function initialize(
         address _incidentResponder,
         uint64[] calldata _initialSchedule,
@@ -148,7 +147,7 @@ contract ProtocolVersions is ProxyAdminOwnedBase, Initializable, Reinitializable
     {
         // Initialization transactions must come from the ProxyAdmin or its owner.
         _assertOnlyProxyAdminOrProxyAdminOwner();
-        if (_initialMinimumProtocolVersion > type(uint128).max) {
+        if (_initialMinimumProtocolVersion == 0 || _initialMinimumProtocolVersion > type(uint128).max) {
             revert ProtocolVersions_InvalidProtocolVersion();
         }
 
@@ -159,9 +158,6 @@ contract ProtocolVersions is ProxyAdminOwnedBase, Initializable, Reinitializable
 
         for (uint256 id = 0; id < _initialSchedule.length; id++) {
             uint64 timestamp = _initialSchedule[id];
-            if (timestamp != 0 && _initialMinimumProtocolVersion == 0) {
-                revert ProtocolVersions_InvalidProtocolVersion();
-            }
             if (timestamp > uint64(block.timestamp) && timestamp < uint64(block.timestamp) + MIN_NOTICE) {
                 revert ProtocolVersions_InsufficientNotice(timestamp);
             }
@@ -177,9 +173,7 @@ contract ProtocolVersions is ProxyAdminOwnedBase, Initializable, Reinitializable
         // pass. With an empty import this just re-emits the seed as the current commitment.
         _refreshScheduleId(0);
 
-        if (_initialMinimumProtocolVersion != 0) {
-            _writeMinimumProtocolVersion(_initialMinimumProtocolVersion);
-        }
+        _writeMinimumProtocolVersion(_initialMinimumProtocolVersion);
 
         incidentResponder = _incidentResponder;
         emit IncidentResponderUpdated(address(0), _incidentResponder);
@@ -232,8 +226,9 @@ contract ProtocolVersions is ProxyAdminOwnedBase, Initializable, Reinitializable
     /// @param protocolVersion Packed semver uint256 (must be non-zero and fit in 128 bits).
     function setMinimumProtocolVersion(uint256 protocolVersion) external {
         _assertOnlyProxyAdminOwner();
-        if (protocolVersion == 0) revert ProtocolVersions_InvalidProtocolVersion();
-        if (protocolVersion > type(uint128).max) revert ProtocolVersions_InvalidProtocolVersion();
+        if (protocolVersion == 0 || protocolVersion > type(uint128).max) {
+            revert ProtocolVersions_InvalidProtocolVersion();
+        }
         _writeMinimumProtocolVersion(protocolVersion);
     }
 

diff --git a/test/L1/ProtocolVersions.t.sol b/test/L1/ProtocolVersions.t.sol
@@ -82,7 +82,7 @@ contract ProtocolVersions_Initialize_Test is ProtocolVersions_TestInit {
         vm.expectEmit(true, true, false, false, address(uninitialized));
         emit IncidentResponderUpdated(address(0), _incidentResponder);
         vm.prank(EIP1967Helper.getAdmin(address(uninitialized)));
-        uninitialized.initialize(_incidentResponder, new uint64[](0), 0);
+        uninitialized.initialize(_incidentResponder, new uint64[](0), 1);
         assertEq(uninitialized.incidentResponder(), _incidentResponder);
     }
 
@@ -92,7 +92,7 @@ contract ProtocolVersions_Initialize_Test is ProtocolVersions_TestInit {
         IProtocolVersions uninitialized = _deployUninitializedProxy();
         vm.expectRevert(IProxyAdminOwnedBase.ProxyAdminOwnedBase_NotProxyAdminOrProxyAdminOwner.selector);
         vm.prank(_nonOwner);
-        uninitialized.initialize(_incidentResponder, new uint64[](0), 0);
+        uninitialized.initialize(_incidentResponder, new uint64[](0), 1);
     }
 
     /// @notice Tests that the initializer imports a preexisting schedule, building the same hash
@@ -170,27 +170,12 @@ contract ProtocolVersions_Initialize_Test is ProtocolVersions_TestInit {
         imported.initialize(address(0), schedule, 42);
     }
 
-    /// @notice Tests that an imported activation cannot omit the minimum protocol version required by nodes.
-    function test_initialize_importWithoutMinimumProtocolVersion_reverts() external {
-        uint64[] memory schedule = new uint64[](1);
-        schedule[0] = 1;
-
+    /// @notice Tests that the initial minimum protocol version is required even with an empty schedule.
+    function test_initialize_zeroMinimumProtocolVersion_reverts() external {
         IProtocolVersions imported = _deployUninitializedProxy();
         vm.expectRevert(IProtocolVersions.ProtocolVersions_InvalidProtocolVersion.selector);
         vm.prank(EIP1967Helper.getAdmin(address(imported)));
-        imported.initialize(address(0), schedule, 0);
-    }
-
-    /// @notice Tests that zero-only imports may leave the minimum protocol version unset.
-    function test_initialize_zeroOnlyScheduleWithoutMinimumProtocolVersion_succeeds() external {
-        uint64[] memory schedule = new uint64[](1);
-
-        IProtocolVersions imported = _deployUninitializedProxy();
-        vm.prank(EIP1967Helper.getAdmin(address(imported)));
-        imported.initialize(address(0), schedule, 0);
-
-        assertEq(imported.getSchedule().length, 1);
-        assertEq(imported.minimumProtocolVersion(), 0);
+        imported.initialize(address(0), new uint64[](0), 0);
     }
 
     /// @notice Tests that the initial minimum protocol version must fit in the node's 128-bit packed semver layout.
@@ -205,14 +190,14 @@ contract ProtocolVersions_Initialize_Test is ProtocolVersions_TestInit {
     function test_initialize_alreadyInitialized_reverts() external {
         vm.expectRevert("Initializable: contract is already initialized");
         vm.prank(EIP1967Helper.getAdmin(address(protocolVersions)));
-        protocolVersions.initialize(address(0), new uint64[](0), 0);
+        protocolVersions.initialize(address(0), new uint64[](0), 1);
     }
 
     /// @notice Tests that the implementation itself cannot be initialized (initializers disabled).
     function test_initialize_implementationDisabled_reverts() external {
         IProtocolVersions impl = IProtocolVersions(EIP1967Helper.getImplementation(address(protocolVersions)));
         vm.expectRevert("Initializable: contract is already initialized");
-        impl.initialize(address(0), new uint64[](0), 0);
+        impl.initialize(address(0), new uint64[](0), 1);
     }
 }
 

diff --git a/test/L1/proofs/BaseTest.t.sol b/test/L1/proofs/BaseTest.t.sol
@@ -114,7 +114,7 @@ contract BaseTest is Test {
         );
         factory.initialize(address(this));
         delayedWETH.initialize(systemConfig);
-        protocolVersions.initialize(address(0), new uint64[](0), 0);
+        protocolVersions.initialize(address(0), new uint64[](0), 1);
     }
 
     /// @dev Rebuilds the schedule registry around a preset schedule and rebinds the verifier to it.

diff --git a/test/deploy/DeployConfig.t.sol b/test/deploy/DeployConfig.t.sol
@@ -63,23 +63,23 @@ contract DeployConfig_Test is Test {
         assertEq(cfg.protocolVersionsInitialMinimumVersion(), 42);
     }
 
-    function test_readMinimumVersion_omitted_defaultsToZero_succeeds() public {
+    function test_readMinimumVersion_omitted_reverts() public {
+        vm.expectRevert("DeployConfig: initial minimum protocol version must be non-zero");
         cfg.readMinimumVersion('{"l1ChainId":1}');
-
-        assertEq(cfg.protocolVersionsInitialMinimumVersion(), 0);
     }
 
     function test_readMinimumVersion_aboveUint128_reverts() public {
         vm.expectRevert("DeployConfig: initial minimum protocol version exceeds uint128");
         cfg.readMinimumVersion('{"protocolVersionsInitialMinimumVersion":340282366920938463463374607431768211456}');
     }
 
-    /// @notice The shipped configs describe chains without a recorded history, so they must keep the initial registry
-    /// state empty.
-    function test_read_localConfig_leavesProtocolVersionsStateEmpty_succeeds() public {
+    /// @notice The shipped configs describe chains without a recorded history, so the imported schedule stays empty.
+    /// The minimum protocol version is required even without recorded upgrade history.
+    function test_read_localConfig_leavesScheduleEmptyWithMinimumVersionSet_succeeds() public {
         cfg.read("deploy-config/local.json");
 
         assertEq(cfg.protocolVersionsInitialSchedule().length, 0);
-        assertEq(cfg.protocolVersionsInitialMinimumVersion(), 0);
+        assertGt(cfg.protocolVersionsInitialMinimumVersion(), 0);
+        assertLe(cfg.protocolVersionsInitialMinimumVersion(), type(uint128).max);
     }
 }
diff --git a/test/deploy/SystemDeploy.t.sol b/test/deploy/SystemDeploy.t.sol
@@ -187,12 +187,9 @@ contract SystemDeploy_Test is Test, SystemDeployAssertions {
     }
 
     /// @notice Pins ProtocolVersions input validation before superchain deployment can broadcast.
-    function test_deploy_initialScheduleWithoutMinimumProtocolVersion_reverts() public {
-        uint64[] memory schedule = new uint64[](1);
-        schedule[0] = 1;
-
+    function test_deploy_zeroInitialMinimumProtocolVersion_reverts() public {
         SystemDeploy.DeployInput memory input = _defaultDeployInput();
-        input.opChainInput.initialUpgradeSchedule = schedule;
+        input.opChainInput.initialMinimumProtocolVersion = 0;
         input.superchainInput.superchainProxyAdminOwner = address(0);
 
         vm.expectRevert(IProtocolVersions.ProtocolVersions_InvalidProtocolVersion.selector);
@@ -485,7 +482,7 @@ contract SystemDeploy_Test is Test, SystemDeployAssertions {
             saltMixer: "system-deploy-test",
             gasLimit: 60_000_000,
             initialUpgradeSchedule: new uint64[](0),
-            initialMinimumProtocolVersion: 0
+            initialMinimumProtocolVersion: 1
         });
     }