diff --git a/src/HelloWorld.sol b/src/HelloWorld.sol
index 35c3e6b..7323a5c 100644
--- a/src/HelloWorld.sol
+++ b/src/HelloWorld.sol
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.20;
 
 contract HelloWorld {
diff --git a/src/Imports.sol b/src/Imports.sol
index 4356bf7..0b15b97 100644
--- a/src/Imports.sol
+++ b/src/Imports.sol
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.20;
 
 import "solmate/tokens/ERC20.sol";
diff --git a/src/Wallet.sol b/src/Wallet.sol
index e1f2849..30e20aa 100644
--- a/src/Wallet.sol
+++ b/src/Wallet.sol
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.20;
 
 contract Wallet {