diff --git a/src/internal/operators/dematerialize.ts b/src/internal/operators/dematerialize.ts
index 28c2c867f2..913e4f0ad8 100644
--- a/src/internal/operators/dematerialize.ts
+++ b/src/internal/operators/dematerialize.ts
@@ -27,9 +27,9 @@ import { OperatorSubscriber } from './OperatorSubscriber';
  * ```ts
  * import { NextNotification, ErrorNotification, of, dematerialize } from 'rxjs';
  *
- * const notifA = <NextNotification<string>>{ kind: 'N', value: 'A' };
- * const notifB = <NextNotification<string>>{ kind: 'N', value: 'B' };
- * const notifE = <ErrorNotification>{ kind: 'E', error: new TypeError('x.toUpperCase is not a function') };
+ * const notifA: NextNotification<string> = { kind: 'N', value: 'A' };
+ * const notifB: NextNotification<string> = { kind: 'N', value: 'B' };
+ * const notifE: ErrorNotification = { kind: 'E', error: new TypeError('x.toUpperCase is not a function') };
  *
  * const materialized = of(notifA, notifB, notifE);
  *