diff --git a/examples/calculator/src/index.tsx b/examples/calculator/src/index.tsx
index 852911990..328248060 100644
--- a/examples/calculator/src/index.tsx
+++ b/examples/calculator/src/index.tsx
@@ -85,7 +85,7 @@ function safeEval(expr: string): string {
     if (tokens.length === 0) return '0';
 
     // Handle initial negative number
-    if (tokens[0] === '-' && tokens.length > 1 && !isNaN(Number(tokens[1]))) {
+    if (tokens[0] === '-' && tokens.length > 1 && !Number.isNaN(Number(tokens[1]))) {
         tokens.splice(0, 2, '-' + tokens[1]);
     }
 
diff --git a/examples/weather/src/index.tsx b/examples/weather/src/index.tsx
index dce3c7425..2dcf862ec 100644
--- a/examples/weather/src/index.tsx
+++ b/examples/weather/src/index.tsx
@@ -201,7 +201,7 @@ async function fetchWeather() {
   }
 }
 
-setInterval(fetchWeather, 5000);
+clearInterval(window.__interval); window.__interval = setInterval(fetchWeather, 5000);
 fetchWeather();
 
 // Gauge does not expose a public setColor() method, so dynamic color
diff --git a/packages/dev-server/src/server.ts b/packages/dev-server/src/server.ts
index 47d4f2b6d..b31a4da89 100644
--- a/packages/dev-server/src/server.ts
+++ b/packages/dev-server/src/server.ts
@@ -380,7 +380,7 @@ export class DevServer {
 
             this._killChild();
 
-            await exitedPromise.catch(() => {});
+            await exitedPromise.catch( => console.error());
 
             if (this._running && this._entryFile) {
                 this._spawnChild();