diff --git a/src/index.ts b/src/index.ts
index b4d76b8e..04582f16 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -39,6 +39,6 @@ export function parse(text: string, ref?: ParsingReference | Date, option?: Pars
 /**
  * A shortcut for {@link en | chrono.en.casual.parseDate()}
  */
-export function parseDate(text: string, ref?: ParsingReference | Date, option?: ParsingOption): Date {
+export function parseDate(text: string, ref?: ParsingReference | Date, option?: ParsingOption): Date | null {
     return casual.parseDate(text, ref, option);
 }