diff --git a/packages/@react-aria/i18n/src/useFilter.ts b/packages/@react-aria/i18n/src/useFilter.ts
index aee067ae546..c84ae63fbec 100644
--- a/packages/@react-aria/i18n/src/useFilter.ts
+++ b/packages/@react-aria/i18n/src/useFilter.ts
@@ -15,11 +15,11 @@ import {useCollator} from './useCollator';
 
 export interface Filter {
   /** Returns whether a string starts with a given substring. */
-  startsWith(string: string, substring: string): boolean,
+  startsWith: (string: string, substring: string) => boolean,
   /** Returns whether a string ends with a given substring. */
-  endsWith(string: string, substring: string): boolean,
+  endsWith: (string: string, substring: string) => boolean,
   /** Returns whether a string contains a given substring. */
-  contains(string: string, substring: string): boolean
+  contains: (string: string, substring: string) => boolean
 }
 
 /**