diff --git a/framework/core/js/src/@types/translator-icu-rich.d.ts b/framework/core/js/src/@types/translator-icu-rich.d.ts
index 08fb52765..a1cefb795 100644
--- a/framework/core/js/src/@types/translator-icu-rich.d.ts
+++ b/framework/core/js/src/@types/translator-icu-rich.d.ts
@@ -1,4 +1,6 @@
 declare module '@askvortsov/rich-icu-message-formatter' {
+  import Mithril from 'mithril';
+
   type IValues = Record<string, any>;
 
   type ITypeHandler = (
@@ -10,16 +12,13 @@ declare module '@askvortsov/rich-icu-message-formatter' {
   ) => string;
   type IRichHandler = (tag: any, values: IValues, contents: string) => any;
 
-  type ValueOrArray<T> = T | ValueOrArray<T>[];
-  type NestedStringArray = ValueOrArray<string>;
-
   export class RichMessageFormatter {
     locale: string | null;
     constructor(locale: string | null, typeHandlers: Record<string, ITypeHandler>, richHandler: IRichHandler);
 
     format(message: string, values: IValues): string;
-    process(message: string, values: IValues): NestedStringArray;
-    rich(message: string, values: IValues): NestedStringArray;
+    process(message: string, values: IValues): Mithril.Children;
+    rich(message: string, values: IValues): Mithril.Children;
   }
 
   export function mithrilRichHandler(tag: any, values: IValues, contents: string): any;