diff --git a/examples/widget-gallery/src/index.ts b/examples/widget-gallery/src/index.ts
index 57b141244..ec688a7fc 100644
--- a/examples/widget-gallery/src/index.ts
+++ b/examples/widget-gallery/src/index.ts
@@ -129,7 +129,7 @@ class WidgetGalleryApp extends Widget {
         }
 
         // Tab switching: 1-6
-        const num = parseInt(event.key);
+        const num = parseInt(event.key, 10);
         if (num >= 1 && num <= 6) {
             this._switchTab(num - 1);
             return true;
diff --git a/packages/ui/src/TreeSelect.ts b/packages/ui/src/TreeSelect.ts
index 652ede256..2c3a59a97 100644
--- a/packages/ui/src/TreeSelect.ts
+++ b/packages/ui/src/TreeSelect.ts
@@ -182,7 +182,7 @@ function _pathsEqual(a: number[], b: number[]): boolean {
 
 function _valuesEqual(a: string[], b: string[]): boolean {
     if (a.length !== b.length) return false;
-    const sortedA = [...a].sort();
+    const sortedA = [...a].sort((a, b) => a - b);
     const sortedB = [...b].sort();
     for (let i = 0; i < sortedA.length; i++) {
         if (sortedA[i] !== sortedB[i]) return false;
diff --git a/packages/ui/src/prompts.ts b/packages/ui/src/prompts.ts
index b92bb28ba..b248a6ac4 100644
--- a/packages/ui/src/prompts.ts
+++ b/packages/ui/src/prompts.ts
@@ -113,7 +113,7 @@ async function promptSelect<T = string>(options: SelectPromptOptions<T>): Promis
                     return;
                 }
                 const n = parseInt(trimmed, 10);
-                if (!isNaN(n) && n >= 1 && n <= choices.length) {
+                if (!Number.isNaN(n) && n >= 1 && n <= choices.length) {
                     rl.close();
                     resolve(choices[n - 1].value);
                     return;