diff --git a/packages/protocol/contracts/test/erc20/FreeMintERC20.sol b/packages/protocol/contracts/test/erc20/FreeMintERC20.sol
index 2e4328c853..b6f0025b35 100644
--- a/packages/protocol/contracts/test/erc20/FreeMintERC20.sol
+++ b/packages/protocol/contracts/test/erc20/FreeMintERC20.sol
@@ -11,9 +11,18 @@ import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 // An ERC20 Token with a mint function anyone can call, for free, to receive
 // 5 tokens.
 contract FreeMintERC20 is ERC20 {
+    error HasMinted();
+
+    mapping(address minter => bool hasMinted) public minters;
+
     constructor(string memory name, string memory symbol) ERC20(name, symbol) {}
 
     function mint(address to) public {
-        _mint(to, 5 * (10 ** decimals()));
+        if (minters[msg.sender]) {
+            revert HasMinted();
+        }
+
+        minters[msg.sender] = true;
+        _mint(to, 50 * (10 ** decimals()));
     }
 }
diff --git a/packages/protocol/contracts/test/erc20/MayFailFreeMintERC20.sol b/packages/protocol/contracts/test/erc20/MayFailFreeMintERC20.sol
index bba5df63e8..98df1dc9f2 100644
--- a/packages/protocol/contracts/test/erc20/MayFailFreeMintERC20.sol
+++ b/packages/protocol/contracts/test/erc20/MayFailFreeMintERC20.sol
@@ -12,10 +12,19 @@ import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 // This token has 50% of failure on transfers so we can
 // test the bridge's error handling.
 contract MayFailFreeMintERC20 is ERC20 {
+    error HasMinted();
+
+    mapping(address minter => bool hasMinted) public minters;
+
     constructor(string memory name, string memory symbol) ERC20(name, symbol) {}
 
     function mint(address to) public {
-        _mint(to, 5 * (10 ** decimals()));
+        if (minters[msg.sender]) {
+            revert HasMinted();
+        }
+
+        minters[msg.sender] = true;
+        _mint(to, 50 * (10 ** decimals()));
     }
 
     function transfer(