diff --git a/static/search.ts b/static/search.ts
index c42da88..e1d6664 100644
--- a/static/search.ts
+++ b/static/search.ts
@@ -1,4 +1,4 @@
-type CommandPaletteItem = {
+interface CommandPaletteItem {
   id: string;
   type: string;
   label: string;
@@ -6,7 +6,7 @@ type CommandPaletteItem = {
   href: string;
   image?: string;
   icon?: string;
-};
+}
 
 const commandPaletteInitializedKey = Symbol('commandPaletteInitialized');
 const globalWindow = window as Window & { [commandPaletteInitializedKey]?: boolean };
diff --git a/static/timezone.ts b/static/timezone.ts
index 6acd2c7..db9efd9 100644
--- a/static/timezone.ts
+++ b/static/timezone.ts
@@ -3,11 +3,11 @@ export {};
 // JST offset from UTC in minutes (UTC+9)
 const jstOffsetMinutes = 9 * 60;
 
-type ParsedBroadcast = {
+interface ParsedBroadcast {
   day: string;
   hour: number;
   minute: number;
-};
+}
 
 const parseBroadcastTime = (value: string | null): { hour: number; minute: number } | null => {
   if (!value || typeof value !== 'string') {