diff --git a/contracts/crowdsale/Crowdsale.sol b/contracts/crowdsale/Crowdsale.sol
index e4cc4eb077d..24c0342f7ae 100644
--- a/contracts/crowdsale/Crowdsale.sol
+++ b/contracts/crowdsale/Crowdsale.sol
@@ -66,7 +66,7 @@ contract Crowdsale {
   }
 
   // low level token purchase function
-  function buyTokens(address beneficiary) payable {
+  function buyTokens(address beneficiary) public payable {
     require(beneficiary != 0x0);
     require(validPurchase());