diff --git a/src/launchpad/NFTLaunchpadCommon.sol b/src/launchpad/NFTLaunchpadCommon.sol
new file mode 100644
index 0000000..f16f68e
--- /dev/null
+++ b/src/launchpad/NFTLaunchpadCommon.sol
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.22;
+
+import { IERC165 } from "@openzeppelin/contracts/interfaces/IERC165.sol";
+
+import { INFTLaunchpad } from "../interfaces/launchpad/INFTLaunchpad.sol";
+
+abstract contract NFTLaunchpadCommon is IERC165, INFTLaunchpad {
+  /// @dev Returns whether the contract supports the NFT launchpad interface.
+  function supportsInterface(bytes4 interfaceId) public view virtual returns (bool) {
+    return interfaceId == type(INFTLaunchpad).interfaceId;
+  }
+}
diff --git a/src/mock/launchpad/SampleNFT1155Launchpad.sol b/src/mock/launchpad/SampleNFT1155Launchpad.sol
index 21a34fa..b070646 100644
--- a/src/mock/launchpad/SampleNFT1155Launchpad.sol
+++ b/src/mock/launchpad/SampleNFT1155Launchpad.sol
@@ -3,9 +3,9 @@ pragma solidity ^0.8.19;
 
 import { ERC1155 } from "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
 import { AccessControl } from "@openzeppelin/contracts/access/AccessControl.sol";
-import { INFTLaunchpad } from "../../interfaces/launchpad/INFTLaunchpad.sol";
+import { NFTLaunchpadCommon } from "../../launchpad/NFTLaunchpadCommon.sol";
 
-contract SampleNFT1155Launchpad is ERC1155, AccessControl, INFTLaunchpad {
+contract SampleNFT1155Launchpad is ERC1155, AccessControl, NFTLaunchpadCommon {
   bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
 
   constructor(address admin, address minter, string memory uri_) ERC1155(uri_) {
@@ -31,7 +31,13 @@ contract SampleNFT1155Launchpad is ERC1155, AccessControl, INFTLaunchpad {
     amounts[1] = 1;
   }
 
-  function supportsInterface(bytes4 interfaceId) public view virtual override(ERC1155, AccessControl) returns (bool) {
-    return interfaceId == type(INFTLaunchpad).interfaceId || super.supportsInterface(interfaceId);
+  function supportsInterface(bytes4 interfaceId)
+    public
+    view
+    virtual
+    override(ERC1155, AccessControl, NFTLaunchpadCommon)
+    returns (bool)
+  {
+    return super.supportsInterface(interfaceId);
   }
 }
diff --git a/src/mock/launchpad/SampleNFT721Launchpad.sol b/src/mock/launchpad/SampleNFT721Launchpad.sol
index 934d68b..6317bee 100644
--- a/src/mock/launchpad/SampleNFT721Launchpad.sol
+++ b/src/mock/launchpad/SampleNFT721Launchpad.sol
@@ -2,11 +2,12 @@
 pragma solidity ^0.8.19;
 
 import { SampleERC721 } from "../SampleERC721.sol";
-import { ERC165 } from "@openzeppelin/contracts/utils/introspection/ERC165.sol";
 
-import { INFTLaunchpad } from "../../interfaces/launchpad/INFTLaunchpad.sol";
+import { SampleERC721 } from "../SampleERC721.sol";
+import { ERC721Common } from "../../ERC721Common.sol";
+import { NFTLaunchpadCommon } from "../../launchpad/NFTLaunchpadCommon.sol";
 
-contract SampleNFT721Launchpad is SampleERC721, INFTLaunchpad {
+contract SampleNFT721Launchpad is SampleERC721, NFTLaunchpadCommon {
   constructor(string memory name_, string memory symbol_, string memory uri_) SampleERC721(name_, symbol_, uri_) { }
 
   /// @dev Mint NFTs for the launchpad.
@@ -23,7 +24,13 @@ contract SampleNFT721Launchpad is SampleERC721, INFTLaunchpad {
     }
   }
 
-  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
-    return interfaceId == type(INFTLaunchpad).interfaceId || super.supportsInterface(interfaceId);
+  function supportsInterface(bytes4 interfaceId)
+    public
+    view
+    virtual
+    override(ERC721Common, NFTLaunchpadCommon)
+    returns (bool)
+  {
+    return super.supportsInterface(interfaceId);
   }
 }