diff --git a/packages/contracts/src/current/tutorials/Arbitrage/Arbitrage.sol b/packages/contracts/src/current/tutorials/Arbitrage/Arbitrage.sol
index 3ee8b5fbac..3ae2e92b8a 100644
--- a/packages/contracts/src/current/tutorials/Arbitrage/Arbitrage.sol
+++ b/packages/contracts/src/current/tutorials/Arbitrage/Arbitrage.sol
@@ -19,7 +19,7 @@ contract Arbitrage is Ownable {
         proxyAddress = _proxyAddress;
     }
 
-    function setAllowances(address tokenAddress) public onlyOwner {
+    function setAllowances(address tokenAddress) external onlyOwner {
         Token token = Token(tokenAddress);
         token.approve(address(etherDelta), MAX_UINT);
         token.approve(proxyAddress, MAX_UINT);