diff --git a/apps/client/src/widgets/view_widgets/calendar_view.ts b/apps/client/src/widgets/view_widgets/calendar_view.ts
index febac6f4d..8da330ed8 100644
--- a/apps/client/src/widgets/view_widgets/calendar_view.ts
+++ b/apps/client/src/widgets/view_widgets/calendar_view.ts
@@ -676,7 +676,7 @@ export async function getFullCalendarLocale(locale: string) {
             return (await import("@fullcalendar/core/locales/ru")).default;
         case "ja":
             return (await import("@fullcalendar/core/locales/ja")).default;
-        case "pt_BR":
+        case "pt_br":
             return (await import("@fullcalendar/core/locales/pt-br")).default;
         case "uk":
             return (await import("@fullcalendar/core/locales/uk")).default;
diff --git a/apps/server/src/services/i18n.ts b/apps/server/src/services/i18n.ts
index c849ecc5a..edc2115b8 100644
--- a/apps/server/src/services/i18n.ts
+++ b/apps/server/src/services/i18n.ts
@@ -18,7 +18,7 @@ const DAYJS_LOADER: Record<LOCALE_IDS, () => Promise<typeof import("dayjs/locale
     "he": () => import("dayjs/locale/he.js"),
     "ja": () => import("dayjs/locale/ja.js"),
     "ku": () => import("dayjs/locale/ku.js"),
-    "pt_BR": () => import("dayjs/locale/pt_BR.js"),
+    "pt_br": () => import("dayjs/locale/pt-br.js"),
     "ro": () => import("dayjs/locale/ro.js"),
     "ru": () => import("dayjs/locale/ru.js"),
     "tw": () => import("dayjs/locale/zh-tw.js"),
diff --git a/packages/commons/src/lib/i18n.ts b/packages/commons/src/lib/i18n.ts
index 24d775658..5f2470aa3 100644
--- a/packages/commons/src/lib/i18n.ts
+++ b/packages/commons/src/lib/i18n.ts
@@ -16,7 +16,7 @@ const UNSORTED_LOCALES: Locale[] = [
     { id: "es", name: "Español", electronLocale: "es" },
     { id: "fr", name: "Français", electronLocale: "fr" },
     { id: "ja", name: "日本語", electronLocale: "ja" },
-    { id: "pt_BR", name: "Português (Brasil)", electronLocale: "pt-BR" },
+    { id: "pt_br", name: "Português (Brasil)", electronLocale: "pt-BR" },
     { id: "ro", name: "Română", electronLocale: "ro" },
     { id: "ru", name: "Русский", electronLocale: "ru" },
     { id: "tw", name: "繁體中文", electronLocale: "zh_TW" },