diff --git a/contracts/Marketplace.sol b/contracts/Marketplace.sol
index 36177d8..87055d9 100644
--- a/contracts/Marketplace.sol
+++ b/contracts/Marketplace.sol
@@ -10,7 +10,6 @@ import "./libs/Utils.sol";
 
 contract Marketplace is Collateral, Proofs {
   using EnumerableSet for EnumerableSet.Bytes32Set;
-  using EnumerableSet for EnumerableSet.AddressSet;
   using Utils for EnumerableSet.Bytes32Set;
 
   type RequestId is bytes32;