diff --git a/contracts/asset-proxy/contracts/src/ERC1155Proxy.sol b/contracts/asset-proxy/contracts/src/ERC1155Proxy.sol
index 48a0324ec4..e1a17ff2b1 100644
--- a/contracts/asset-proxy/contracts/src/ERC1155Proxy.sol
+++ b/contracts/asset-proxy/contracts/src/ERC1155Proxy.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.5.5;
+pragma solidity ^0.5.9;
 
 import "./MixinAuthorizable.sol";
 
diff --git a/contracts/asset-proxy/contracts/src/StaticCallProxy.sol b/contracts/asset-proxy/contracts/src/StaticCallProxy.sol
index c65ef60a37..9b1a7a92ef 100644
--- a/contracts/asset-proxy/contracts/src/StaticCallProxy.sol
+++ b/contracts/asset-proxy/contracts/src/StaticCallProxy.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.5.5;
+pragma solidity ^0.5.9;
 
 
 contract StaticCallProxy {
diff --git a/contracts/asset-proxy/contracts/test/TestStaticCallTarget.sol b/contracts/asset-proxy/contracts/test/TestStaticCallTarget.sol
index a5bf3da795..28da79c634 100644
--- a/contracts/asset-proxy/contracts/test/TestStaticCallTarget.sol
+++ b/contracts/asset-proxy/contracts/test/TestStaticCallTarget.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.5.5;
+pragma solidity ^0.5.9;
 
 import "@0x/contracts-utils/contracts/src/LibBytes.sol";