diff --git a/contracts/interfaces/HubPoolInterface.sol b/contracts/interfaces/HubPoolInterface.sol
index 49292e215..128f906f5 100644
--- a/contracts/interfaces/HubPoolInterface.sol
+++ b/contracts/interfaces/HubPoolInterface.sol
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
diff --git a/contracts/interfaces/LpTokenFactoryInterface.sol b/contracts/interfaces/LpTokenFactoryInterface.sol
index 6e8012ff8..9e60636ef 100644
--- a/contracts/interfaces/LpTokenFactoryInterface.sol
+++ b/contracts/interfaces/LpTokenFactoryInterface.sol
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 /**
diff --git a/contracts/interfaces/SpokePoolInterface.sol b/contracts/interfaces/SpokePoolInterface.sol
index cfc448d9b..9eec066c1 100644
--- a/contracts/interfaces/SpokePoolInterface.sol
+++ b/contracts/interfaces/SpokePoolInterface.sol
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 /**
diff --git a/contracts/interfaces/SpokePoolMessageHandler.sol b/contracts/interfaces/SpokePoolMessageHandler.sol
index 7360ddac8..a5bd63fd4 100644
--- a/contracts/interfaces/SpokePoolMessageHandler.sol
+++ b/contracts/interfaces/SpokePoolMessageHandler.sol
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 // This interface is expected to be implemented by any contract that expects to receive messages from the SpokePool.
diff --git a/contracts/interfaces/V3SpokePoolInterface.sol b/contracts/interfaces/V3SpokePoolInterface.sol
index 8e5773114..ea19237c3 100644
--- a/contracts/interfaces/V3SpokePoolInterface.sol
+++ b/contracts/interfaces/V3SpokePoolInterface.sol
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 // Contains structs and functions used by SpokePool contracts to facilitate universal settlement.