diff --git a/index.d.ts b/index.d.ts
index 2f31856..b999044 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,5 +1 @@
-import Observable = require("zen-observable");
-export { Observable };
-export type Observer<T> = ZenObservable.Observer<T>;
-export type Subscription = ZenObservable.Subscription;
-export type Subscriber<T> = ZenObservable.Subscriber<T>;
+export * from "./module";
diff --git a/module.d.ts b/module.d.ts
index 6d1e0ee..c06c4d2 100644
--- a/module.d.ts
+++ b/module.d.ts
@@ -1 +1,58 @@
-export * from "./index";
+export interface Subscription {
+  closed: boolean;
+  unsubscribe(): void;
+}
+
+interface SubscriptionObserver<T> {
+  closed: boolean;
+  next(value: T): void;
+  error(errorValue: any): void;
+  complete(): void;
+}
+
+export interface Observer<T> {
+  start?(subscription: Subscription): any;
+  next?(value: T): void;
+  error?(errorValue: any): void;
+  complete?(): void;
+}
+
+export type Subscriber<T> = (
+  observer: SubscriptionObserver<T>,
+) => void | (() => void) | Subscription;
+
+interface ObservableLike<T> {
+  subscribe?: Subscriber<T> | undefined;
+  [Symbol.observable](): Observable<T> | ObservableLike<T>;
+}
+
+export declare class Observable<T> {
+  constructor(subscriber: Subscriber<T>);
+
+  // For backwards compatibility when super(subscriber) is transpiled to
+  // Observable.call(this, subscriber), which typically happens when the
+  // Observable class is compiled to ES5 function contructor syntax.
+  static call<R>(instance: Observable<R>, subscriber: Subscriber<R>): undefined;
+  static apply<R>(instance: Observable<R>, args: IArguments | [Subscriber<R>]): undefined;
+
+  subscribe(observer: Observer<T>): Subscription;
+  subscribe(
+    onNext: (value: T) => void,
+    onError?: (error: any) => void,
+    onComplete?: () => void,
+  ): Subscription;
+
+  [Symbol.observable](): Observable<T>;
+
+  forEach(callback: (value: T) => void): Promise<void>;
+  map<R>(callback: (value: T) => R): Observable<R>;
+  filter<S extends T>(callback: (value: T) => value is S): Observable<S>;
+  filter(callback: (value: T) => boolean): Observable<T>;
+  reduce(callback: (previousValue: T, currentValue: T) => T, initialValue?: T): Observable<T>;
+  reduce<R>(callback: (previousValue: R, currentValue: T) => R, initialValue?: R): Observable<R>;
+  flatMap<R>(callback: (value: T) => ObservableLike<R>): Observable<R>;
+  concat<R>(...observable: Array<Observable<R>>): Observable<R>;
+
+  static from<R>(observable: Observable<R> | ObservableLike<R> | ArrayLike<R>): Observable<R>;
+  static of<R>(...items: R[]): Observable<R>;
+}
diff --git a/package-lock.json b/package-lock.json
index 2bc8a93..29efd88 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -8,7 +8,6 @@
       "version": "1.1.0",
       "license": "MIT",
       "dependencies": {
-        "@types/zen-observable": "0.8.3",
         "zen-observable": "0.8.15"
       },
       "devDependencies": {
@@ -1732,11 +1731,6 @@
         "@types/node": "*"
       }
     },
-    "node_modules/@types/zen-observable": {
-      "version": "0.8.3",
-      "resolved": "https://registry.npmjs.org/@types/zen-observable/-/zen-observable-0.8.3.tgz",
-      "integrity": "sha512-fbF6oTd4sGGy0xjHPKAt+eS2CrxJ3+6gQ3FGcBoIJR2TLAyCkCyI8JqZNy+FeON0AhVgNJoUumVoZQjBFUqHkw=="
-    },
     "node_modules/@ungap/promise-all-settled": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/@ungap/promise-all-settled/-/promise-all-settled-1.1.2.tgz",
@@ -4611,11 +4605,6 @@
         "@types/node": "*"
       }
     },
-    "@types/zen-observable": {
-      "version": "0.8.3",
-      "resolved": "https://registry.npmjs.org/@types/zen-observable/-/zen-observable-0.8.3.tgz",
-      "integrity": "sha512-fbF6oTd4sGGy0xjHPKAt+eS2CrxJ3+6gQ3FGcBoIJR2TLAyCkCyI8JqZNy+FeON0AhVgNJoUumVoZQjBFUqHkw=="
-    },
     "@ungap/promise-all-settled": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/@ungap/promise-all-settled/-/promise-all-settled-1.1.2.tgz",
diff --git a/package.json b/package.json
index f881520..f882756 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,7 @@
   "license": "MIT",
   "main": "index.js",
   "module": "module.js",
-  "types": "index.d.ts",
+  "types": "module.d.ts",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/apollographql/zen-observable-ts.git"
@@ -20,7 +20,6 @@
     "test": "mocha tests/bundle.js"
   },
   "dependencies": {
-    "@types/zen-observable": "0.8.3",
     "zen-observable": "0.8.15"
   },
   "devDependencies": {