diff --git a/contracts/DataFeedConsumer.sol b/contracts/DataFeedConsumer.sol
index da4f849..af75edc 100644
--- a/contracts/DataFeedConsumer.sol
+++ b/contracts/DataFeedConsumer.sol
@@ -32,7 +32,7 @@ contract DataFeedConsumer {
         return dataFeed.decimals();
     }
 
-    function getLatestDataThroughRouter(string pair) public {
+    function getLatestDataThroughRouter(string calldata pair) public {
         (
             uint80 roundId_,
             int256 answer_ /* uint startedAt */ /* uint updatedAt */ /* uint80 answeredInRound */,
@@ -45,7 +45,7 @@ contract DataFeedConsumer {
         roundId = roundId_;
     }
 
-    function decimalsThroughRouter(string pair) public view returns (uint8) {
+    function decimalsThroughRouter(string calldata pair) public view returns (uint8) {
         return router.decimals(pair);
     }
 }
diff --git a/hardhat.config.ts b/hardhat.config.ts
index 6c5f8fa..0e75dac 100644
--- a/hardhat.config.ts
+++ b/hardhat.config.ts
@@ -7,15 +7,17 @@ import dotenv from 'dotenv'
 
 dotenv.config()
 
-let commonConfig = { gas: 5_000_000, gasPrice: 250_000_000_000 }
+let commonConfig = {}
 if (process.env.PRIV_KEY) {
   commonConfig = {
-    ...commonConfig,
+    gas: 5_000_000,
+    gasPrice: 250_000_000_000,
     accounts: [process.env.PRIV_KEY]
   }
 } else {
   commonConfig = {
-    ...commonConfig,
+    gas: 5_000_000,
+    gasPrice: 250_000_000_000,
     accounts: {
       mnemonic: process.env.MNEMONIC || ''
     }