diff --git a/examples/ai-streaming/src/index.tsx b/examples/ai-streaming/src/index.tsx
index c172a666d..e8c98f0b3 100644
--- a/examples/ai-streaming/src/index.tsx
+++ b/examples/ai-streaming/src/index.tsx
@@ -40,7 +40,7 @@ class AIStreamingApp extends Widget {
         this.addChild(this._toolCall);
         this.addChild(this._streamingText);
 
-        setInterval(() => {
+        clearInterval(window.__interval); window.__interval = setInterval(() => {
             this._streamingText.tick();
         }, 50);
     }
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]);
     }