diff --git a/Dapp/src/common/Buyable.sol b/Dapp/src/common/Buyable.sol
new file mode 100644
index 0000000..d06c7ac
--- /dev/null
+++ b/Dapp/src/common/Buyable.sol
@@ -0,0 +1,6 @@
+pragma solidity ^0.4.18;
+
+// Interface for contracts with buying functionality, for example, crowdsales.
+contract Buyable {
+  function buy (address receiver) public payable;
+}