diff --git a/contracts/.solhint.json b/contracts/.solhint.json
index 108f3996..59577431 100644
--- a/contracts/.solhint.json
+++ b/contracts/.solhint.json
@@ -7,11 +7,17 @@
     "contract-name-camelcase": "off",
     "const-name-snakecase": "off",
     "func-name-mixedcase": "off",
-    "func-visibility": ["error", { "ignoreConstructors": true }],
+    "func-visibility": [
+      "error",
+      {
+        "ignoreConstructors": true
+      }
+    ],
     "max-line-length": ["error", 123],
     "named-parameters-mapping": "warn",
     "no-empty-blocks": "off",
     "not-rely-on-time": "off",
-    "var-name-mixedcase": "off"
+    "var-name-mixedcase": "off",
+    "gas-calldata-parameters": "warn"
   }
 }
diff --git a/contracts/package.json b/contracts/package.json
index fa2b9b64..24055f4e 100644
--- a/contracts/package.json
+++ b/contracts/package.json
@@ -55,7 +55,7 @@
     "dotenv": "^16.4.5",
     "ethers": "^6.12.0",
     "hardhat": "^2.22.3",
-    "solhint": "^4.5.4",
+    "solhint": "^5.0.3",
     "solhint-plugin-prettier": "^0.1.0"
   }
 }
diff --git a/contracts/src/AttestationRegistry.sol b/contracts/src/AttestationRegistry.sol
index 8d49f6b4..89de57b5 100644
--- a/contracts/src/AttestationRegistry.sol
+++ b/contracts/src/AttestationRegistry.sol
@@ -221,7 +221,7 @@ contract AttestationRegistry is OwnableUpgradeable {
    * @notice Bulk revokes a list of attestations for the given identifiers
    * @param attestationIds the IDs of the attestations to revoke
    */
-  function bulkRevoke(bytes32[] memory attestationIds) external {
+  function bulkRevoke(bytes32[] calldata attestationIds) external {
     for (uint256 i = 0; i < attestationIds.length; i = uncheckedInc256(i)) {
       revoke(attestationIds[i]);
     }
diff --git a/contracts/src/PortalRegistry.sol b/contracts/src/PortalRegistry.sol
index c8da6fea..0e771981 100644
--- a/contracts/src/PortalRegistry.sol
+++ b/contracts/src/PortalRegistry.sol
@@ -9,7 +9,6 @@ import { DefaultPortal } from "./DefaultPortal.sol";
 import { Portal } from "./types/Structs.sol";
 import { IRouter } from "./interfaces/IRouter.sol";
 import { IPortal } from "./interfaces/IPortal.sol";
-import { uncheckedInc256 } from "./Common.sol";
 
 /**
  * @title Portal Registry
@@ -198,10 +197,10 @@ contract PortalRegistry is OwnableUpgradeable {
    */
   function deployDefaultPortal(
     address[] calldata modules,
-    string memory name,
-    string memory description,
+    string calldata name,
+    string calldata description,
     bool isRevocable,
-    string memory ownerName
+    string calldata ownerName
   ) external onlyAllowlisted(msg.sender) {
     DefaultPortal defaultPortal = new DefaultPortal(modules, address(router));
     register(address(defaultPortal), name, description, isRevocable, ownerName);
diff --git a/contracts/src/examples/portals/EASPortal.sol b/contracts/src/examples/portals/EASPortal.sol
index a7b24139..b36271b6 100644
--- a/contracts/src/examples/portals/EASPortal.sol
+++ b/contracts/src/examples/portals/EASPortal.sol
@@ -91,7 +91,7 @@ contract EASPortal is AbstractPortal {
    *                  as this ID won't be incremented before the end of the transaction.
    *                  If you need to check the attestation ID, please use the `replace` method.
    */
-  function bulkAttest(AttestationRequest[] memory attestationsRequests) external payable {
+  function bulkAttest(AttestationRequest[] calldata attestationsRequests) external payable {
     for (uint256 i = 0; i < attestationsRequests.length; i = uncheckedInc256(i)) {
       attest(attestationsRequests[i]);
     }
diff --git a/contracts/src/examples/portals/PausablePortal.sol b/contracts/src/examples/portals/PausablePortal.sol
index 2940c286..9b01e6fb 100644
--- a/contracts/src/examples/portals/PausablePortal.sol
+++ b/contracts/src/examples/portals/PausablePortal.sol
@@ -3,10 +3,8 @@ pragma solidity 0.8.21;
 
 import { Pausable } from "@openzeppelin/contracts/security/Pausable.sol";
 import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
-import { IERC165 } from "@openzeppelin/contracts/utils/introspection/ERC165.sol";
 import { AbstractPortal } from "../../abstracts/AbstractPortal.sol";
-import { Attestation, AttestationPayload } from "../../types/Structs.sol";
-import { IPortal } from "../../interfaces/IPortal.sol";
+import { AttestationPayload } from "../../types/Structs.sol";
 
 /**
  * @title Pausable Portal
diff --git a/contracts/src/stdlib/IndexerModule.sol b/contracts/src/stdlib/IndexerModule.sol
index 7c7f6c3a..a30b6f5c 100644
--- a/contracts/src/stdlib/IndexerModule.sol
+++ b/contracts/src/stdlib/IndexerModule.sol
@@ -77,7 +77,7 @@ contract IndexerModule is AbstractModule {
    * @param subject The subject to retrieve attestation IDs for.
    * @return An array of attestation IDs.
    */
-  function getAttestationIdsBySubject(bytes memory subject) external view returns (bytes32[] memory) {
+  function getAttestationIdsBySubject(bytes calldata subject) external view returns (bytes32[] memory) {
     return attestationIdsBySubject[subject];
   }
 
@@ -88,7 +88,7 @@ contract IndexerModule is AbstractModule {
    * @return An array of attestation IDs.
    */
   function getAttestationIdsBySubjectBySchema(
-    bytes memory subject,
+    bytes calldata subject,
     bytes32 schemaId
   ) external view returns (bytes32[] memory) {
     return attestationIdsBySubjectBySchema[subject][schemaId];
@@ -129,7 +129,7 @@ contract IndexerModule is AbstractModule {
    */
   function getAttestationIdsByPortalBySubject(
     address portal,
-    bytes memory subject
+    bytes calldata subject
   ) external view returns (bytes32[] memory) {
     return attestationIdsByPortalBySubject[portal][subject];
   }
diff --git a/contracts/src/stdlib/IndexerModuleV2.sol b/contracts/src/stdlib/IndexerModuleV2.sol
index 360d65cd..51f640ed 100644
--- a/contracts/src/stdlib/IndexerModuleV2.sol
+++ b/contracts/src/stdlib/IndexerModuleV2.sol
@@ -94,7 +94,7 @@ contract IndexerModuleV2 is AbstractModuleV2 {
    * @param subject The subject to retrieve attestation IDs for.
    * @return An array of attestation IDs.
    */
-  function getAttestationIdsBySubject(bytes memory subject) external view returns (bytes32[] memory) {
+  function getAttestationIdsBySubject(bytes calldata subject) external view returns (bytes32[] memory) {
     return attestationIdsBySubject[subject];
   }
 
@@ -105,7 +105,7 @@ contract IndexerModuleV2 is AbstractModuleV2 {
    * @return An array of attestation IDs.
    */
   function getAttestationIdsBySubjectBySchema(
-    bytes memory subject,
+    bytes calldata subject,
     bytes32 schemaId
   ) external view returns (bytes32[] memory) {
     return attestationIdsBySubjectBySchema[subject][schemaId];
@@ -146,7 +146,7 @@ contract IndexerModuleV2 is AbstractModuleV2 {
    */
   function getAttestationIdsByPortalBySubject(
     address portal,
-    bytes memory subject
+    bytes calldata subject
   ) external view returns (bytes32[] memory) {
     return attestationIdsByPortalBySubject[portal][subject];
   }
diff --git a/contracts/test/PortalRegistry.t.sol b/contracts/test/PortalRegistry.t.sol
index 029e7b4f..6d039f8b 100644
--- a/contracts/test/PortalRegistry.t.sol
+++ b/contracts/test/PortalRegistry.t.sol
@@ -12,8 +12,6 @@ import { ModuleRegistryMock } from "./mocks/ModuleRegistryMock.sol";
 import { ValidPortalMock } from "./mocks/ValidPortalMock.sol";
 import { InvalidPortalMock } from "./mocks/InvalidPortalMock.sol";
 import { IPortalImplementation } from "./mocks/IPortalImplementation.sol";
-import "../src/PortalRegistry.sol";
-import "../src/PortalRegistry.sol";
 
 contract PortalRegistryTest is Test {
   address public user = makeAddr("user");
diff --git a/contracts/test/examples/portals/PausablePortal.t.sol b/contracts/test/examples/portals/PausablePortal.t.sol
index 0493a328..e0dc3475 100644
--- a/contracts/test/examples/portals/PausablePortal.t.sol
+++ b/contracts/test/examples/portals/PausablePortal.t.sol
@@ -9,11 +9,10 @@ import { AttestationPayload } from "../../../src/types/Structs.sol";
 import { AttestationRegistryMock } from "../../mocks/AttestationRegistryMock.sol";
 import { PortalRegistryMock } from "../../mocks/PortalRegistryMock.sol";
 import { ModuleRegistryMock } from "../../mocks/ModuleRegistryMock.sol";
-import { Pausable } from "@openzeppelin/contracts/security/Pausable.sol";
 import { IERC165 } from "@openzeppelin/contracts/utils/introspection/ERC165.sol";
 
 contract PausablePortalTest is Test {
-  address portalOwner = makeAddr("portalOwner");
+  address public portalOwner = makeAddr("portalOwner");
   PausablePortal public pausablePortal;
   address[] public modules = new address[](0);
   ModuleRegistryMock public moduleRegistryMock = new ModuleRegistryMock();
diff --git a/contracts/test/mocks/AttestationRegistryMock.sol b/contracts/test/mocks/AttestationRegistryMock.sol
index fbc28757..b07c44f8 100644
--- a/contracts/test/mocks/AttestationRegistryMock.sol
+++ b/contracts/test/mocks/AttestationRegistryMock.sol
@@ -85,7 +85,7 @@ contract AttestationRegistryMock {
     return attestations[attestationId];
   }
 
-  function generateAttestationId(uint256 id) internal view returns (bytes32) {
+  function generateAttestationId(uint256 id) internal pure returns (bytes32) {
     // This is a mock implementation, 1000 is considered as chain prefix
     return bytes32(abi.encode(1000 + id));
   }
diff --git a/contracts/test/mocks/EASRegistryMock.sol b/contracts/test/mocks/EASRegistryMock.sol
index 8653ce22..c8b4f7d8 100644
--- a/contracts/test/mocks/EASRegistryMock.sol
+++ b/contracts/test/mocks/EASRegistryMock.sol
@@ -13,7 +13,7 @@ contract EASRegistryMock is IEAS {
     return attestations[uid];
   }
 
-  function addAttestation(Attestation memory attestation) external {
+  function addAttestation(Attestation calldata attestation) external {
     attestations[attestation.uid] = attestation;
   }
 }
diff --git a/contracts/test/mocks/PortalRegistryMock.sol b/contracts/test/mocks/PortalRegistryMock.sol
index 75f86e2d..b115e9c3 100644
--- a/contracts/test/mocks/PortalRegistryMock.sol
+++ b/contracts/test/mocks/PortalRegistryMock.sol
@@ -14,10 +14,10 @@ contract PortalRegistryMock {
 
   function register(
     address id,
-    string memory name,
-    string memory description,
+    string calldata name,
+    string calldata description,
     bool isRevocable,
-    string memory ownerName
+    string calldata ownerName
   ) external {
     Portal memory newPortal = Portal(id, msg.sender, new address[](0), isRevocable, name, description, ownerName);
     portals[id] = newPortal;
diff --git a/contracts/test/mocks/PortalRegistryNotAllowlistedMock.sol b/contracts/test/mocks/PortalRegistryNotAllowlistedMock.sol
index 7d5ad8f1..c6f39545 100644
--- a/contracts/test/mocks/PortalRegistryNotAllowlistedMock.sol
+++ b/contracts/test/mocks/PortalRegistryNotAllowlistedMock.sol
@@ -14,10 +14,10 @@ contract PortalRegistryNotAllowlistedMock {
 
   function register(
     address id,
-    string memory name,
-    string memory description,
+    string calldata name,
+    string calldata description,
     bool isRevocable,
-    string memory ownerName
+    string calldata ownerName
   ) external {
     Portal memory newPortal = Portal(id, msg.sender, new address[](0), isRevocable, name, description, ownerName);
     portals[id] = newPortal;