diff --git a/contracts/contracts/l1/rollup/Rollup.sol b/contracts/contracts/l1/rollup/Rollup.sol
index 4a6567619..905913f94 100644
--- a/contracts/contracts/l1/rollup/Rollup.sol
+++ b/contracts/contracts/l1/rollup/Rollup.sol
@@ -194,6 +194,8 @@ contract Rollup is IRollup, OwnableUpgradeable, PausableUpgradeable {
 
         (uint256 memPtr, bytes32 _batchHash) = _loadBatchHeader(_batchHeader);
         uint256 _batchIndex = BatchHeaderCodecV0.getBatchIndex(memPtr);
+        // check batch index is 0
+        require(_batchIndex == 0, "invalid batch index");
         bytes32 _postStateRoot = BatchHeaderCodecV0.getPostStateHash(memPtr);
         require(_postStateRoot != bytes32(0), "zero state root");
         // check all fields except `dataHash` and `lastBlockHash` are zero
diff --git a/contracts/contracts/test/Rollup.t.sol b/contracts/contracts/test/Rollup.t.sol
index 95d49eda1..d29606ad9 100644
--- a/contracts/contracts/test/Rollup.t.sol
+++ b/contracts/contracts/test/Rollup.t.sol
@@ -546,6 +546,15 @@ contract RollupTest is L1MessageBaseTest {
     function test_importGenesisBlock_succeeds() public {
         bytes memory batchHeader;
         bytes32 bytesData1 = bytes32(uint256(1));
+        // invalid batch index, revert
+        batchHeader = new bytes(249);
+        assembly {
+            mstore(add(batchHeader, add(0x20, 1)), shl(192, 1)) // batchIndex = 1
+        }
+        hevm.expectRevert("invalid batch index");
+        hevm.prank(multisig);
+        rollup.importGenesisBatch(batchHeader);
+
         // zero state root, revert
         batchHeader = new bytes(249);
         hevm.expectRevert("zero state root");