diff --git a/src/hooks/useCryptoPrices.js b/src/hooks/useCryptoPrices.js
index 66ef2fd..43f5f89 100644
--- a/src/hooks/useCryptoPrices.js
+++ b/src/hooks/useCryptoPrices.js
@@ -36,14 +36,14 @@ async function fetchPrices() {
 function toWei(usdTarget, tokenPriceUsd) {
   if (!tokenPriceUsd || tokenPriceUsd <= 0) return undefined;
   const raw = usdTarget / tokenPriceUsd;
-  if (!isFinite(raw) || isNaN(raw)) return undefined;
+  if (!isFinite(raw) || Number.isNaN(raw)) return undefined;
   try { return parseEther(raw.toFixed(8)); } catch { return undefined; }
 }
 
 function toHuman(usdTarget, tokenPriceUsd, decimals = 5) {
   if (!tokenPriceUsd || tokenPriceUsd <= 0) return undefined;
   const raw = usdTarget / tokenPriceUsd;
-  if (!isFinite(raw) || isNaN(raw)) return undefined;
+  if (!isFinite(raw) || Number.isNaN(raw)) return undefined;
   return raw.toFixed(decimals);
 }
 
diff --git a/src/utils/formatters.js b/src/utils/formatters.js
index 824f601..a24c97c 100644
--- a/src/utils/formatters.js
+++ b/src/utils/formatters.js
@@ -1,5 +1,5 @@
 export const formatFileSize = (bytes) => {
-  if (typeof bytes !== 'number' || isNaN(bytes) || bytes <= 0) return '0 Bytes';
+  if (typeof bytes !== 'number' || Number.isNaN(bytes) || bytes <= 0) return '0 Bytes';
   const k = 1024;
   const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB'];
   const i = Math.floor(Math.log(bytes) / Math.log(k));