diff --git a/contracts/inputs/IInputBox.sol b/contracts/inputs/IInputBox.sol
index 245e7c4c..396c9962 100644
--- a/contracts/inputs/IInputBox.sol
+++ b/contracts/inputs/IInputBox.sol
@@ -53,4 +53,7 @@ interface IInputBox {
         address appContract,
         uint256 index
     ) external view returns (bytes32);
+
+    /// @notice Get number of block in which contract was deployed
+    function getDeploymentBlockNumber() external view returns (uint256);
 }
diff --git a/contracts/inputs/InputBox.sol b/contracts/inputs/InputBox.sol
index a3fe3cc1..e170c4c0 100644
--- a/contracts/inputs/InputBox.sol
+++ b/contracts/inputs/InputBox.sol
@@ -8,9 +8,16 @@ import {CanonicalMachine} from "../common/CanonicalMachine.sol";
 import {Inputs} from "../common/Inputs.sol";
 
 contract InputBox is IInputBox {
+    /// @notice Deployment block number
+    uint256 immutable _deploymentBlockNumber;
+
     /// @notice Mapping of application contract addresses to arrays of input hashes.
     mapping(address => bytes32[]) private _inputBoxes;
 
+    constructor() {
+        _deploymentBlockNumber = block.number;
+    }
+
     /// @inheritdoc IInputBox
     function addInput(
         address appContract,
@@ -65,4 +72,14 @@ contract InputBox is IInputBox {
     ) external view override returns (bytes32) {
         return _inputBoxes[appContract][index];
     }
+
+    /// @inheritdoc IInputBox
+    function getDeploymentBlockNumber()
+        external
+        view
+        override
+        returns (uint256)
+    {
+        return _deploymentBlockNumber;
+    }
 }
diff --git a/test/inputs/InputBox.t.sol b/test/inputs/InputBox.t.sol
index 4430bca8..4c56ffeb 100644
--- a/test/inputs/InputBox.t.sol
+++ b/test/inputs/InputBox.t.sol
@@ -18,6 +18,12 @@ contract InputBoxTest is Test {
         _inputBox = new InputBox();
     }
 
+    function testDeploymentBlockNumber(uint256 blockNumber) public {
+        vm.roll(blockNumber);
+        _inputBox = new InputBox();
+        assertEq(_inputBox.getDeploymentBlockNumber(), blockNumber);
+    }
+
     function testNoInputs(address appContract) public view {
         assertEq(_inputBox.getNumberOfInputs(appContract), 0);
     }