diff --git a/solidity/contracts/Oracle.sol b/solidity/contracts/Oracle.sol
index 9283cb9..d786695 100644
--- a/solidity/contracts/Oracle.sol
+++ b/solidity/contracts/Oracle.sol
@@ -14,8 +14,6 @@ import {OracleAccessController} from './access/OracleAccessController.sol';
 import {OracleTypehash} from './utils/OracleTypehash.sol';
 
 contract Oracle is IOracle, OracleAccessController {
-  using ValidatorLib for *;
-
   /// @inheritdoc IOracle
   mapping(bytes32 _requestId => uint256 _finalizedAt) public finalizedAt;
 
diff --git a/solidity/libraries/ValidatorLib.sol b/solidity/libraries/ValidatorLib.sol
index 8c694ca..e69da78 100644
--- a/solidity/libraries/ValidatorLib.sol
+++ b/solidity/libraries/ValidatorLib.sol
@@ -20,7 +20,7 @@ library ValidatorLib {
    * @param _request The request to compute the id for
    * @return _id The id the request
    */
-  function _getId(IOracle.Request calldata _request) public pure returns (bytes32 _id) {
+  function _getId(IOracle.Request memory _request) internal pure returns (bytes32 _id) {
     _id = keccak256(abi.encode(_request));
   }
 
@@ -30,7 +30,7 @@ library ValidatorLib {
    * @param _response The response to compute the id for
    * @return _id The id the response
    */
-  function _getId(IOracle.Response calldata _response) public pure returns (bytes32 _id) {
+  function _getId(IOracle.Response memory _response) internal pure returns (bytes32 _id) {
     _id = keccak256(abi.encode(_response));
   }
 
@@ -40,7 +40,7 @@ library ValidatorLib {
    * @param _dispute The dispute to compute the id for
    * @return _id The id the dispute
    */
-  function _getId(IOracle.Dispute calldata _dispute) public pure returns (bytes32 _id) {
+  function _getId(IOracle.Dispute memory _dispute) internal pure returns (bytes32 _id) {
     _id = keccak256(abi.encode(_dispute));
   }
 
@@ -52,9 +52,9 @@ library ValidatorLib {
    * @return _responseId The id the response
    */
   function _validateResponse(
-    IOracle.Request calldata _request,
-    IOracle.Response calldata _response
-  ) public pure returns (bytes32 _responseId) {
+    IOracle.Request memory _request,
+    IOracle.Response memory _response
+  ) internal pure returns (bytes32 _responseId) {
     bytes32 _requestId = _getId(_request);
     _responseId = _getId(_response);
 
@@ -69,9 +69,9 @@ library ValidatorLib {
    * @return _disputeId The id the dispute
    */
   function _validateDispute(
-    IOracle.Request calldata _request,
-    IOracle.Dispute calldata _dispute
-  ) public pure returns (bytes32 _disputeId) {
+    IOracle.Request memory _request,
+    IOracle.Dispute memory _dispute
+  ) internal pure returns (bytes32 _disputeId) {
     bytes32 _requestId = _getId(_request);
     _disputeId = _getId(_dispute);
 
@@ -86,9 +86,9 @@ library ValidatorLib {
    * @return _disputeId The id the dispute
    */
   function _validateDispute(
-    IOracle.Response calldata _response,
-    IOracle.Dispute calldata _dispute
-  ) public pure returns (bytes32 _disputeId) {
+    IOracle.Response memory _response,
+    IOracle.Dispute memory _dispute
+  ) internal pure returns (bytes32 _disputeId) {
     bytes32 _responseId = _getId(_response);
     _disputeId = _getId(_dispute);
 
@@ -105,10 +105,10 @@ library ValidatorLib {
    * @return _disputeId The id the dispute
    */
   function _validateResponseAndDispute(
-    IOracle.Request calldata _request,
-    IOracle.Response calldata _response,
-    IOracle.Dispute calldata _dispute
-  ) public pure returns (bytes32 _responseId, bytes32 _disputeId) {
+    IOracle.Request memory _request,
+    IOracle.Response memory _response,
+    IOracle.Dispute memory _dispute
+  ) internal pure returns (bytes32 _responseId, bytes32 _disputeId) {
     bytes32 _requestId = _getId(_request);
     _responseId = _getId(_response);
     _disputeId = _getId(_dispute);