diff --git a/contracts/Mocks/IUSDT.sol b/contracts/Mocks/IUSDT.sol
index 8bd9ead..4425677 100644
--- a/contracts/Mocks/IUSDT.sol
+++ b/contracts/Mocks/IUSDT.sol
@@ -1,3 +1,5 @@
+pragma solidity ^0.5.8;
+
 contract ERC20Basic {
     uint public _totalSupply;
     function totalSupply() public view returns (uint);