diff --git a/web/apps/photos/src/components/Sidebar.tsx b/web/apps/photos/src/components/Sidebar.tsx
index f2b4cc7b12..03ba6964a3 100644
--- a/web/apps/photos/src/components/Sidebar.tsx
+++ b/web/apps/photos/src/components/Sidebar.tsx
@@ -976,6 +976,8 @@ const localeName = (locale: SupportedLocale) => {
             return "اَلْعَرَبِيَّةُ";
         case "tr-TR":
             return "Türkçe";
+        case "cs-CZ":
+            return "čeština";
     }
 };
 
diff --git a/web/packages/base/i18n.ts b/web/packages/base/i18n.ts
index 90c6cfce1c..f5ba2dd1b3 100644
--- a/web/packages/base/i18n.ts
+++ b/web/packages/base/i18n.ts
@@ -36,6 +36,7 @@ export const supportedLocales = [
     "ja-JP" /* Japanese */,
     "ar-SA" /* Arabic */,
     "tr-TR" /* Turkish */,
+    "cs-CZ" /* Czech */,
 ] as const;
 
 /** The type of {@link supportedLocales}. */
@@ -201,6 +202,8 @@ const closestSupportedLocale = (
             return "ar-SA";
         } else if (ls.startsWith("tr")) {
             return "tr-TR";
+        } else if (ls.startsWith("cs")) {
+            return "cs-CZ";
         }
     }