diff --git a/contracts/MoatResolver.sol b/contracts/MoatResolver.sol
index 6519265..91f90a0 100644
--- a/contracts/MoatResolver.sol
+++ b/contracts/MoatResolver.sol
@@ -3,7 +3,7 @@ pragma solidity ^0.4.24;
 import "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
 
 interface AddressRegistry {
-    function getAddr(string name) external returns(address);
+    function getAddr(string name) external view returns(address);
 }
 
 
diff --git a/contracts/bin/MoatAsset.sol b/contracts/bin/MoatAsset.sol
index a526d49..5af7129 100644
--- a/contracts/bin/MoatAsset.sol
+++ b/contracts/bin/MoatAsset.sol
@@ -9,8 +9,8 @@ import "openzeppelin-solidity/contracts/math/SafeMath.sol";
 import "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
 
 interface AddressRegistry {
-    function getAddr(string name) external returns(address);
-    function isApprovedResolver(address user) external returns(bool);
+    function getAddr(string name) external view returns(address);
+    function isApprovedResolver(address user) external view returns(bool);
 }
 
 
diff --git a/contracts/protocols/MoatKyber.sol b/contracts/protocols/MoatKyber.sol
index 1733d6a..31b4a57 100644
--- a/contracts/protocols/MoatKyber.sol
+++ b/contracts/protocols/MoatKyber.sol
@@ -5,8 +5,8 @@ import "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
 
 
 interface AddressRegistry {
-    function getAddr(string name) external returns(address);
-    function isApprovedResolver(address user) external returns(bool);
+    function getAddr(string name) external view returns(address);
+    function isApprovedResolver(address user) external view returns(bool);
 }
 
 interface Resolver {
diff --git a/contracts/protocols/MoatMaker.sol b/contracts/protocols/MoatMaker.sol
index e7ffb90..142627e 100644
--- a/contracts/protocols/MoatMaker.sol
+++ b/contracts/protocols/MoatMaker.sol
@@ -5,8 +5,8 @@ import "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
 
 
 interface AddressRegistry {
-    function getAddr(string name) external returns(address);
-    function isApprovedResolver(address user) external returns(bool);
+    function getAddr(string name) external view returns(address);
+    function isApprovedResolver(address user) external view returns(bool);
 }
 
 interface Resolver {
@@ -22,7 +22,7 @@ interface MakerCDP {
     function free(bytes32 cup, uint wad) external;
     function draw(bytes32 cup, uint wad) external;
     function wipe(bytes32 cup, uint wad) external;
-    function per() external returns (uint ray);
+    function per() external view returns (uint ray);
 }
 
 interface WETHFace {