diff --git a/examples/rss-reader/src/index.tsx b/examples/rss-reader/src/index.tsx
index 2b269cb81..920f57bc9 100644
--- a/examples/rss-reader/src/index.tsx
+++ b/examples/rss-reader/src/index.tsx
@@ -27,12 +27,12 @@ function decodeEntities(value: string): string {
 
   return value.replace(/&(#x?[0-9a-fA-F]+|[a-zA-Z]+);/g, (match, entity: string) => {
     if (entity.startsWith('#x')) {
-      const codePoint = Number.parseInt(entity.slice(2), 16);
+      const codePoint = Number.parseInt(entity.slice(2, 10), 16);
       return Number.isFinite(codePoint) ? String.fromCodePoint(codePoint) : match;
     }
 
     if (entity.startsWith('#')) {
-      const codePoint = Number.parseInt(entity.slice(1), 10);
+      const codePoint = Number.parseInt(entity.slice(1, 10), 10);
       return Number.isFinite(codePoint) ? String.fromCodePoint(codePoint) : match;
     }
 
@@ -188,7 +188,7 @@ function ErrorScreen({ message }: { message: string }) {
 
 function FeedListPane({ items, state }: { items: FeedEntry[]; state: ReturnType<typeof useListState> }) {
   const listRef = useRef<List | null>(null);
-  const mappedItems: ListItem[] = items.map((entry) => ({ label: entry.title, value: entry.link }));
+  const mappedItems: ListItem[] = (items ?? []).map((entry) => ({ label: entry.title, value: entry.link }));
 
   const list = listRef.current ??= new List(
     { items: mappedItems, state },
diff --git a/examples/showcase/src/index.tsx b/examples/showcase/src/index.tsx
index 444be6698..47a52a3e3 100644
--- a/examples/showcase/src/index.tsx
+++ b/examples/showcase/src/index.tsx
@@ -128,7 +128,7 @@ class ShowcaseApp extends Widget {
         if (event.key === 'q' || (event.ctrl && event.key === 'c')) return false;
 
         // Tab switching: 1-5
-        const num = parseInt(event.key);
+        const num = parseInt(event.key, 10);
         if (num >= 1 && num <= 5) {
             this.switchTab(num - 1);
             return true;
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..aabe6cff6 100644
--- a/packages/ui/src/TreeSelect.ts
+++ b/packages/ui/src/TreeSelect.ts
@@ -182,8 +182,8 @@ 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 sortedB = [...b].sort();
+    const sortedA = [...a].sort((a, b) => a - b);
+    const sortedB = [...b].sort((a, b) => a - b);
     for (let i = 0; i < sortedA.length; i++) {
         if (sortedA[i] !== sortedB[i]) return false;
     }
diff --git a/scripts/build-registry.ts b/scripts/build-registry.ts
index f84844538..b4cecbd00 100644
--- a/scripts/build-registry.ts
+++ b/scripts/build-registry.ts
@@ -44,7 +44,7 @@ export function collectDeps(content: string): string[] {
   const deps = new Set<string>();
   let m: RegExpExecArray | null;
   while ((m = re.exec(content)) !== null) deps.add(m[1]!);
-  return [...deps].sort();
+  return [...deps].sort((a, b) => a - b);
 }
 
 export function toSlug(name: string): string {
@@ -289,7 +289,7 @@ function parseOptionsInterface(content: string, optionsTypeName: string): ApiPro
   }
   const local = parseFields(m[2]!);
   // Prepend inherited fields; a locally-redeclared field overrides the parent.
-  const localNames = new Set(local.map(p => p.name));
+  const localNames = new Set((local ?? []).map(p => p.name));
   return [...inherited.filter(p => !localNames.has(p.name)), ...local];
 }