diff --git a/packages/material-ui/src/locale/index.d.ts b/packages/material-ui/src/locale/index.d.ts
index cfa0b2cf076090..fab491e0e8f26a 100644
--- a/packages/material-ui/src/locale/index.d.ts
+++ b/packages/material-ui/src/locale/index.d.ts
@@ -1,3 +1,4 @@
+export const azAZ: object;
 export const deDE: object;
 export const enUS: object;
 export const esES: object;