diff --git a/contracts/protocols/mainnet/resolvers/maker/helpers.sol b/contracts/protocols/mainnet/resolvers/maker/helpers.sol
index f07c1e9..d49df1d 100644
--- a/contracts/protocols/mainnet/resolvers/maker/helpers.sol
+++ b/contracts/protocols/mainnet/resolvers/maker/helpers.sol
@@ -4,7 +4,7 @@ import {DSMath} from "../../common/math.sol";
 import {VatLike, SpotLike, JugLike, InstaMcdAddress} from "./interface.sol";
 
 
-contract Helpers is DSMath {
+abstract contract Helpers is DSMath {
     /**
      * @dev get MakerDAO MCD Address contract
      */
diff --git a/contracts/protocols/mainnet/resolvers/maker/main.sol b/contracts/protocols/mainnet/resolvers/maker/main.sol
index 66e5a8b..854eb88 100644
--- a/contracts/protocols/mainnet/resolvers/maker/main.sol
+++ b/contracts/protocols/mainnet/resolvers/maker/main.sol
@@ -4,7 +4,7 @@ pragma experimental ABIEncoderV2;
 import {Helpers} from "./helpers.sol";
 import {InstaMcdAddress, VatLike, CdpsLike, ManagerLike, PotLike} from "./interface.sol";
 
-contract VaultResolver is Helpers {
+abstract contract VaultResolver is Helpers {
     function getVaults(address owner)
         external
         view
diff --git a/contracts/protocols/polygon/resolvers/aave/v2/helpers.sol b/contracts/protocols/polygon/resolvers/aave/v2/helpers.sol
index 705dd68..4d28c65 100644
--- a/contracts/protocols/polygon/resolvers/aave/v2/helpers.sol
+++ b/contracts/protocols/polygon/resolvers/aave/v2/helpers.sol
@@ -12,7 +12,7 @@ import {
     TokenInterface
 } from "./interface.sol";
 
-contract Helpers is DSMath {
+abstract contract Helpers is DSMath {
     /**
      * @dev Return ethereum address
      */
diff --git a/contracts/protocols/polygon/resolvers/aave/v2/main.sol b/contracts/protocols/polygon/resolvers/aave/v2/main.sol
index e6ce973..ef3e425 100644
--- a/contracts/protocols/polygon/resolvers/aave/v2/main.sol
+++ b/contracts/protocols/polygon/resolvers/aave/v2/main.sol
@@ -4,7 +4,7 @@ pragma experimental ABIEncoderV2;
 import { Helpers } from "./helpers.sol";
 import { AaveAddressProvider, AaveProtocolDataProvider, AaveLendingPool } from "./interface.sol";
 
-contract Resolver is Helpers {
+abstract contract Resolver is Helpers {
     function getPosition(address user, address[] memory tokens) public view returns(AaveUserTokenData[] memory, AaveUserData memory) {
         AaveAddressProvider addrProvider = AaveAddressProvider(getAaveAddressProvider());
         uint length = tokens.length;