diff --git a/src/AbortError.ts b/src/AbortError.ts
index f41949f..22178ac 100644
--- a/src/AbortError.ts
+++ b/src/AbortError.ts
@@ -21,7 +21,7 @@ export class AbortError extends Error {
 /**
  * Checks whether given `error` is an `AbortError`.
  */
-export function isAbortError(error: unknown): boolean {
+export function isAbortError(error: unknown): error is Error {
   return (
     typeof error === 'object' &&
     error !== null &&