diff --git a/src/app/api/goals/route.ts b/src/app/api/goals/route.ts
index 0d616ebd3..b4b83346b 100644
--- a/src/app/api/goals/route.ts
+++ b/src/app/api/goals/route.ts
@@ -239,7 +239,7 @@ try {
   let safeDeadline: string | null = null;
   if (typeof deadline === "string") {
     const d = new Date(deadline);
-    if (!isNaN(d.getTime())) {
+    if (!Number.isNaN(d.getTime())) {
       d.setUTCHours(23, 59, 59, 999);
       safeDeadline = d.toISOString();
     }
diff --git a/src/app/api/local-coding/sync/route.ts b/src/app/api/local-coding/sync/route.ts
index 6b444d7f4..1c62a85ae 100644
--- a/src/app/api/local-coding/sync/route.ts
+++ b/src/app/api/local-coding/sync/route.ts
@@ -279,7 +279,7 @@ export async function GET(req: NextRequest) {
 
   const { searchParams } = new URL(req.url);
   const rawDays = parseInt(searchParams.get("days") || "30", 10);
-  const days = validateDays(isNaN(rawDays) ? DEFAULT_DAYS : rawDays);
+  const days = validateDays(Number.isNaN(rawDays) ? DEFAULT_DAYS : rawDays);
   const fromDate = new Date();
   fromDate.setDate(fromDate.getDate() - days);
   const fromDateStr = fromDate.toISOString().slice(0, 10);