diff --git a/api_guard/dist/types/operators/index.d.ts b/api_guard/dist/types/operators/index.d.ts
index 4df5ca75dbd..b973c8cface 100644
--- a/api_guard/dist/types/operators/index.d.ts
+++ b/api_guard/dist/types/operators/index.d.ts
@@ -1,5 +1,3 @@
-import { ObservableInput } from "..";
-
 export declare function audit<T>(durationSelector: (value: T) => ObservableInput<any>): MonoTypeOperatorFunction<T>;
 
 export declare function auditTime<T>(duration: number, scheduler?: SchedulerLike): MonoTypeOperatorFunction<T>;
@@ -241,7 +239,7 @@ export declare function retry<T>(config: RetryConfig): MonoTypeOperatorFunction<
 export interface RetryConfig {
     count?: number;
     delay?: number | ((error: any, retryCount: number) => ObservableInput<any>);
-    resetOnSuccess?: boolean;  b
+    resetOnSuccess?: boolean;
 }
 
 export declare function retryWhen<T>(notifier: (errors: Observable<any>) => Observable<any>): MonoTypeOperatorFunction<T>;
diff --git a/spec-dtslint/operators/sample-spec.ts b/spec-dtslint/operators/sample-spec.ts
index 48b011f0b9a..647e00a88e9 100644
--- a/spec-dtslint/operators/sample-spec.ts
+++ b/spec-dtslint/operators/sample-spec.ts
@@ -1,11 +1,77 @@
 import { of } from 'rxjs';
 import { sample } from 'rxjs/operators';
+import { asInteropObservable } from '../../spec/helpers/interop-helper';
 
 it('should enforce parameter', () => {
-  const a = of(1, 2, 3).pipe(sample()); // $ExpectError
+  of(1, 2, 3).pipe(sample()); // $ExpectError
 });
 
 it('should accept observable as notifier parameter', () => {
-  const a = of(1, 2, 3).pipe(sample(of(4))); // $ExpectType Observable<number>
-  const b = of(1, 2, 3).pipe(sample(of('a'))); // $ExpectType Observable<number>
+  of(1, 2, 3).pipe(sample(of(4))); // $ExpectType Observable<number>
+  of(1, 2, 3).pipe(sample(of('a'))); // $ExpectType Observable<number>
+});
+
+it('should accept interop observable notifier', () => {
+  of(1, 2, 3).pipe(sample(asInteropObservable(of(true)))); // $ExpectType Observable<number>
+});
+
+it('should accept promise notifier', () => {
+  of(1, 2, 3).pipe(sample(Promise.resolve(true))); // $ExpectType Observable<number>
+});
+
+it('should async iterable notifier', () => {
+  const asyncRange = {
+    from: 1,
+    to: 2,
+    [Symbol.asyncIterator]() {
+      return {
+        current: this.from,
+        last: this.to,
+        async next() {
+          await Promise.resolve();
+          const done = (this.current > this.last);
+          return {
+            done,
+            value: done ? this.current++ : undefined
+          };
+        }
+      };
+    }
+  };
+  of(1, 2, 3).pipe(sample(asyncRange)); // $ExpectType Observable<number>
+});
+
+it('should accept iterable notifier', () => {
+  const syncRange = {
+    from: 1,
+    to: 2,
+    [Symbol.iterator]() {
+      return {
+        current: this.from,
+        last: this.to,
+        next() {
+          const done = (this.current > this.last);
+          return {
+            done,
+            value: done ? this.current++ : undefined
+          };
+        }
+      };
+    }
+  };
+  of(1, 2, 3).pipe(sample(syncRange)); // $ExpectType Observable<number>
+});
+
+it('should accept readable stream notifier', () => {
+  const readableStream = new ReadableStream<string>({
+    pull(controller) {
+      controller.enqueue('x');
+      controller.close();
+    },
+  });
+  of(1, 2, 3).pipe(sample(readableStream)); // $ExpectType Observable<number>
+});
+
+it('should enforce types of the notifier', () => {
+  of(1, 2, 3).pipe(sample(8)); // $ExpectError
 });