diff --git a/spec-dtslint/operators/distinct-spec.ts b/spec-dtslint/operators/distinct-spec.ts
index 3386ce2bd07..35025f34cf5 100644
--- a/spec-dtslint/operators/distinct-spec.ts
+++ b/spec-dtslint/operators/distinct-spec.ts
@@ -1,5 +1,7 @@
-import { of } from 'rxjs';
+import { firstValueFrom, ObservableInput, of } from 'rxjs';
+import { asInteropObservable } from '../../spec/helpers/interop-helper';
 import { distinct } from 'rxjs/operators';
+import { ReadableStreamLike } from '../../src/internal/types';
 
 it('should infer correctly', () => {
   const o = of(1, 2, 3).pipe(distinct()); // $ExpectType Observable<number>
@@ -10,10 +12,79 @@ it('should accept a keySelector', () => {
   const o = of({ name: 'Tim' } as Person).pipe(distinct(person => person.name)); // $ExpectType Observable<Person>
 });
 
-it('should accept flushes', () => {
+it('should accept observable flush', () => {
   const o = of(1, 2, 3).pipe(distinct(n => n, of('t', 'i', 'm'))); // $ExpectType Observable<number>
 });
 
+it('should accept interop observable flush', () => {
+  of(1, 2, 3).pipe(distinct(n => n, asInteropObservable(of('t', 'i', 'm')))); // $ExpectType Observable<number>
+});
+
+it('should accept array-like flush', () => {
+  of(1, 2, 3).pipe(distinct(n => n, [1,2,3])); // $ExpectType Observable<number>
+});
+
+it('should accept promise flush', () => {
+  of(1, 2, 3).pipe(distinct(n => n, Promise.resolve())); // $ExpectType Observable<number>
+});
+
+it('should accept async iterable flush', () => {
+  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(distinct(n => n, asyncRange)); // $ExpectType Observable<number>
+});
+
+it('should accept iterable flush', () => {
+  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(distinct(n => n, syncRange)); // $ExpectType Observable<number>
+});
+
+it('should accept readable stream flush', () => {
+  const readable: ReadableStreamLike<string> = new ReadableStream<string>({
+    pull(controller) {
+      controller.enqueue('x');
+      controller.close();
+    },
+  });
+  of(1, 2, 3).pipe(distinct(n => n, readable)); // $ExpectType Observable<number>
+});
+
+it('should error with unsupported flush', () => {
+  of(1, 2, 3).pipe(distinct(n => n, {})); // $ExpectError
+});
+
 it('should enforce types', () => {
   const o = of(1, 2, 3).pipe(distinct('F00D')); // $ExpectError
 });