diff --git a/src/Hevm.sol b/src/Hevm.sol
index 7a655f2..7e121c3 100644
--- a/src/Hevm.sol
+++ b/src/Hevm.sol
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: MIT
+// SPDX-License-Identifier: Unlicense
 pragma solidity ^0.8.0;
 
 interface IHevm {
@@ -8,6 +8,13 @@ interface IHevm {
     // Set block.number to newNumber
     function roll(uint256 newNumber) external;
 
+    // Add the condition b to the assumption base for the current branch
+    // This function is almost identical to require
+    function assume(bool b) external;
+
+    // Sets the eth balance of usr to amt
+    function deal(address usr, uint256 amt) external;
+
     // Loads a storage slot from an address
     function load(address where, bytes32 slot) external returns (bytes32);
 
@@ -15,16 +22,33 @@ interface IHevm {
     function store(address where, bytes32 slot, bytes32 value) external;
 
     // Signs data (privateKey, digest) => (r, v, s)
-    function sign(uint256 privateKey, bytes32 digest) external returns (uint8 r, bytes32 v, bytes32 s);
+    function sign(
+        uint256 privateKey,
+        bytes32 digest
+    ) external returns (uint8 r, bytes32 v, bytes32 s);
 
     // Gets address for a given private key
-    function addr(uint256 privateKey) external returns (address account);
+    function addr(uint256 privateKey) external returns (address addr);
 
     // Performs a foreign function call via terminal
-    function ffi(string[] calldata inputs) external returns (bytes memory result);
+    function ffi(
+        string[] calldata inputs
+    ) external returns (bytes memory result);
 
     // Performs the next smart contract call with specified `msg.sender`
     function prank(address newSender) external;
+
+    // Creates a new fork with the given endpoint and the latest block and returns the identifier of the fork
+    function createFork(string calldata urlOrAlias) external returns (uint256);
+
+    // Takes a fork identifier created by createFork and sets the corresponding forked state as active
+    function selectFork(uint256 forkId) external;
+
+    // Returns the identifier of the current fork
+    function activeFork() external returns (uint256);
+
+    // Labels the address in traces
+    function label(address addr, string calldata label) external;
 }
 
 IHevm constant vm = IHevm(0x7109709ECfa91a80626fF3989D68f67F5b1DD12D);