diff --git a/.gitmodules b/.gitmodules
index 4075a17..49c7d0f 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,3 +7,6 @@
 [submodule "contracts/lib/solidity-merkle-trees"]
 	path = contracts/lib/solidity-merkle-trees
 	url = git@github.com:michaelkaplan13/solidity-merkle-trees.git
+[submodule "contracts/lib/chainlink"]
+	path = contracts/lib/chainlink
+	url = https://github.com/smartcontractkit/chainlink
diff --git a/contracts/lib/chainlink b/contracts/lib/chainlink
new file mode 160000
index 0000000..883c9f9
--- /dev/null
+++ b/contracts/lib/chainlink
@@ -0,0 +1 @@
+Subproject commit 883c9f9059c259ca17454703b57521ea9ac166cb
diff --git a/contracts/remappings.txt b/contracts/remappings.txt
index 0f5b009..a1aebd0 100644
--- a/contracts/remappings.txt
+++ b/contracts/remappings.txt
@@ -1,2 +1,3 @@
 @solidity-merkle-trees=lib/solidity-merkle-trees/src/
 @subnet-evm=lib/teleporter/contracts/lib/subnet-evm/contracts/
+@chainlink=lib/chainlink/contracts/src/v0.8/shared/
diff --git a/contracts/src/PriceFeedImporter.sol b/contracts/src/PriceFeedImporter.sol
index d8d6f90..a50851a 100644
--- a/contracts/src/PriceFeedImporter.sol
+++ b/contracts/src/PriceFeedImporter.sol
@@ -6,6 +6,7 @@
 pragma solidity 0.8.18;
 
 import {EVMEventInfo, EventImporter} from "./EventImporter.sol";
+import {AggregatorV3Interface} from "@chainlink/interfaces/AggregatorV3Interface.sol";
 
 /**
  * THIS IS AN EXAMPLE CONTRACT THAT USES UN-AUDITED CODE.
@@ -72,7 +73,13 @@ contract PriceFeedImporter is EventImporter, AggregatorV3Interface {
         _;
     }
 
-    constructor(bytes32 sourceBlockchainID_, address sourceOracleAggregator_, uint8 decimals_, string memory description_, uint256 version_) {
+    constructor(
+        bytes32 sourceBlockchainID_,
+        address sourceOracleAggregator_,
+        uint8 decimals_,
+        string memory description_,
+        uint256 version_
+    ) {
         sourceBlockchainID = sourceBlockchainID_;
         sourceOracleAggregator = sourceOracleAggregator_;
         decimals = decimals_;
@@ -80,23 +87,6 @@ contract PriceFeedImporter is EventImporter, AggregatorV3Interface {
         version = version_;
     }
 
-    function latestAnswer() external view returns (int256) {
-        (, int256 answer,,,) = latestRoundData();
-        return answer;
-    }
-
-    function latestRound() external view returns (uint256) {
-        (uint80 roundID,,,,) = latestRoundData();
-        return roundID;
-    }
-
-    // solhint-disable-next-line private-vars-leading-underscore
-    function getAnswer(uint256 _roundID) external view returns (int256) {
-        if (_roundID > 0xFFFFFFFF) return 0;
-        (, int256 answer,,,) = getRoundData(uint80(_roundID));
-        return answer;
-    }
-
     // solhint-disable-next-line private-vars-leading-underscore
     function getRoundData(uint80 _roundID) public view returns (uint80, int256, uint256, uint256, uint80) {
         Round memory round = rounds[_roundID];
diff --git a/contracts/test/PriceFeedImporterTests.sol b/contracts/test/PriceFeedImporterTests.sol
index fc09566..892d74b 100644
--- a/contracts/test/PriceFeedImporterTests.sol
+++ b/contracts/test/PriceFeedImporterTests.sol
@@ -23,6 +23,7 @@ contract PriceFeedImporterTest is Test {
     address public constant SOURCE_ORACLE_AGGREGATOR = 0x154baB1FC1D87fF641EeD0E9Bc0f8a50D880D2B6;
 
     PriceFeedImporterMock public priceFeedImporter;
+    bytes32 public ANSWER_UPDATED_EVENT_SIGNATURE;
 
     event AnswerUpdated(int256 currentAnswer, uint80 roundID, uint256 updatedAt);
     event EventImported(
@@ -35,6 +36,7 @@ contract PriceFeedImporterTest is Test {
 
     function setUp() public virtual {
         priceFeedImporter = new PriceFeedImporterMock();
+        ANSWER_UPDATED_EVENT_SIGNATURE = priceFeedImporter.ANSWER_UPDATED_EVENT_SIGNATURE();
     }
 
     function testSetPriceFeed() public {
@@ -57,20 +59,27 @@ contract PriceFeedImporterTest is Test {
     function testIncreasingRoundID() public {
         priceFeedImporter.importEvent(buildEVMEvent(0, 0, 1));
         priceFeedImporter.importEvent(buildEVMEvent(0, 1, 1));
-        vm.revertWith("roundID should be monotonically increasing");
+        vm.expectRevert("roundID should be monotonically increasing");
         priceFeedImporter.importEvent(buildEVMEvent(0, 0, 1));
+        vm.expectRevert("roundID should be monotonically increasing");
+        priceFeedImporter.importEvent(buildEVMEvent(0, 1, 1));
     }
 
     function testHistoricalRoundData() public {
-        priceFeedImporter.importEvent(buildEVMEvent(0, 0, 1));
-        priceFeedImporter.importEvent(buildEVMEvent(0, 1, 1));
-        vm.revertWith("roundID should be monotonically increasing");
-        priceFeedImporter.importEvent(buildEVMEvent(0, 0, 1));
+        priceFeedImporter.importEvent(buildEVMEvent(10, 0, 1));
+        priceFeedImporter.importEvent(buildEVMEvent(11, 1, 1));
+        (, int256 answer,,,) = priceFeedImporter.getRoundData(0);
+        assertEq(answer, 10);
+        (, answer,,,) = priceFeedImporter.getRoundData(1);
+        assertEq(answer, 11);
+        vm.expectRevert("No data");
+        (, answer,,,) = priceFeedImporter.getRoundData(2);
     }
 
-    function buildEVMEvent(int256 answer, uint80 roundID, uint256 updatedAt) private view returns (EVMEventInfo memory) {
+    uint256 blockNumber = 0;
+    function buildEVMEvent(int256 answer, uint80 roundID, uint256 updatedAt) private returns (EVMEventInfo memory) {
         bytes32[] memory topics = new bytes32[](3);
-        topics[0] = priceFeedImporter.ANSWER_UPDATED_EVENT_SIGNATURE();
+        topics[0] = ANSWER_UPDATED_EVENT_SIGNATURE;
         topics[1] = bytes32(uint256(answer));
         topics[2] = bytes32(uint256(uint80(roundID)));
 
@@ -80,9 +89,11 @@ contract PriceFeedImporterTest is Test {
             data: abi.encode(bytes32(updatedAt))
         });
 
+        blockNumber += 1;
+
         return EVMEventInfo({
             blockchainID: bytes32(0),
-            blockNumber: 1,
+            blockNumber: blockNumber,
             txIndex: 0,
             logIndex: 0,
             log: log