diff --git a/lib/flow-typed.config.json b/lib/flow-typed.config.json
--- a/lib/flow-typed.config.json
+++ b/lib/flow-typed.config.json
@@ -9,6 +9,7 @@
     "serviceworkers",
     "webassembly",
     "jsx",
-    "html"
+    "html",
+    "streams"
   ]
 }
diff --git a/lib/flow-typed/environments/streams.js b/lib/flow-typed/environments/streams.js
new file mode 100644
--- /dev/null
+++ b/lib/flow-typed/environments/streams.js
@@ -0,0 +1,136 @@
+// flow-typed signature: e6e6768618776352dd676f63502aea4d
+// flow-typed version: 40e7dfcbd5/streams/flow_>=v0.261.x
+
+type TextEncodeOptions = { options?: boolean, ... };
+
+declare class ReadableStreamController {
+  constructor(
+    stream: ReadableStream,
+    underlyingSource: UnderlyingSource,
+    size: number,
+    highWaterMark: number,
+  ): void,
+
+  desiredSize: number,
+
+  close(): void,
+  enqueue(chunk: any): void,
+  error(error: Error): void,
+}
+
+declare class ReadableStreamBYOBRequest {
+  constructor(controller: ReadableStreamController, view: $TypedArray): void,
+
+  view: $TypedArray,
+
+  respond(bytesWritten: number): ?any,
+  respondWithNewView(view: $TypedArray): ?any,
+}
+
+declare class ReadableByteStreamController extends ReadableStreamController {
+  constructor(
+    stream: ReadableStream,
+    underlyingSource: UnderlyingSource,
+    highWaterMark: number,
+  ): void,
+
+  byobRequest: ReadableStreamBYOBRequest,
+}
+
+declare class ReadableStreamReader {
+  constructor(stream: ReadableStream): void,
+
+  closed: boolean,
+
+  cancel(reason: string): void,
+  read(): Promise<{
+    value: ?any,
+    done: boolean,
+    ...
+  }>,
+  releaseLock(): void,
+}
+
+declare interface UnderlyingSource {
+  autoAllocateChunkSize?: number,
+  type?: string,
+
+  start?: (controller: ReadableStreamController) => ?Promise<void>,
+  pull?: (controller: ReadableStreamController) => ?Promise<void>,
+  cancel?: (reason: string) => ?Promise<void>,
+}
+
+declare class TransformStream {
+  readable: ReadableStream,
+  writable: WritableStream,
+};
+
+interface PipeThroughTransformStream {
+  readable: ReadableStream,
+  writable: WritableStream,
+}
+
+type PipeToOptions = {
+  preventClose?: boolean,
+  preventAbort?: boolean,
+  preventCancel?: boolean,
+  ...
+};
+
+type QueuingStrategy  = {
+  highWaterMark: number,
+  size(chunk: ?any): number,
+  ...
+};
+
+declare class ReadableStream {
+  constructor(
+    underlyingSource: ?UnderlyingSource,
+    queuingStrategy: ?QueuingStrategy,
+  ): void,
+
+  locked: boolean,
+
+  cancel(reason: string): void,
+  getReader(): ReadableStreamReader,
+  pipeThrough(transform: PipeThroughTransformStream, options: ?any): void,
+  pipeTo(dest: WritableStream, options: ?PipeToOptions): Promise<void>,
+  tee(): [ReadableStream, ReadableStream],
+};
+
+declare interface WritableStreamController {
+  error(error: Error): void,
+}
+
+declare interface UnderlyingSink {
+  autoAllocateChunkSize?: number,
+  type?: string,
+
+  abort?: (reason: string) => ?Promise<void>,
+  close?: (controller: WritableStreamController) => ?Promise<void>,
+  start?: (controller: WritableStreamController) => ?Promise<void>,
+  write?: (chunk: any, controller: WritableStreamController) => ?Promise<void>,
+}
+
+declare interface WritableStreamWriter {
+  closed: Promise<any>,
+  desiredSize?: number,
+  ready: Promise<any>,
+
+  abort(reason: string): ?Promise<any>,
+  close(): Promise<any>,
+  releaseLock(): void,
+  write(chunk: any): Promise<any>,
+}
+
+declare class WritableStream {
+  constructor(
+    underlyingSink: ?UnderlyingSink,
+    queuingStrategy: QueuingStrategy,
+  ): void,
+
+  locked: boolean,
+
+  abort(reason: string): void,
+  getWriter(): WritableStreamWriter,
+}
diff --git a/services/electron-update-server/flow-typed.config.json b/services/electron-update-server/flow-typed.config.json
--- a/services/electron-update-server/flow-typed.config.json
+++ b/services/electron-update-server/flow-typed.config.json
@@ -9,6 +9,7 @@
     "serviceworkers",
     "webassembly",
     "jsx",
-    "html"
+    "html",
+    "streams"
   ]
 }
diff --git a/services/electron-update-server/flow-typed/environments/streams.js b/services/electron-update-server/flow-typed/environments/streams.js
new file mode 100644
--- /dev/null
+++ b/services/electron-update-server/flow-typed/environments/streams.js
@@ -0,0 +1,136 @@
+// flow-typed signature: e6e6768618776352dd676f63502aea4d
+// flow-typed version: 40e7dfcbd5/streams/flow_>=v0.261.x
+
+type TextEncodeOptions = { options?: boolean, ... };
+
+declare class ReadableStreamController {
+  constructor(
+    stream: ReadableStream,
+    underlyingSource: UnderlyingSource,
+    size: number,
+    highWaterMark: number,
+  ): void,
+
+  desiredSize: number,
+
+  close(): void,
+  enqueue(chunk: any): void,
+  error(error: Error): void,
+}
+
+declare class ReadableStreamBYOBRequest {
+  constructor(controller: ReadableStreamController, view: $TypedArray): void,
+
+  view: $TypedArray,
+
+  respond(bytesWritten: number): ?any,
+  respondWithNewView(view: $TypedArray): ?any,
+}
+
+declare class ReadableByteStreamController extends ReadableStreamController {
+  constructor(
+    stream: ReadableStream,
+    underlyingSource: UnderlyingSource,
+    highWaterMark: number,
+  ): void,
+
+  byobRequest: ReadableStreamBYOBRequest,
+}
+
+declare class ReadableStreamReader {
+  constructor(stream: ReadableStream): void,
+
+  closed: boolean,
+
+  cancel(reason: string): void,
+  read(): Promise<{
+    value: ?any,
+    done: boolean,
+    ...
+  }>,
+  releaseLock(): void,
+}
+
+declare interface UnderlyingSource {
+  autoAllocateChunkSize?: number,
+  type?: string,
+
+  start?: (controller: ReadableStreamController) => ?Promise<void>,
+  pull?: (controller: ReadableStreamController) => ?Promise<void>,
+  cancel?: (reason: string) => ?Promise<void>,
+}
+
+declare class TransformStream {
+  readable: ReadableStream,
+  writable: WritableStream,
+};
+
+interface PipeThroughTransformStream {
+  readable: ReadableStream,
+  writable: WritableStream,
+}
+
+type PipeToOptions = {
+  preventClose?: boolean,
+  preventAbort?: boolean,
+  preventCancel?: boolean,
+  ...
+};
+
+type QueuingStrategy  = {
+  highWaterMark: number,
+  size(chunk: ?any): number,
+  ...
+};
+
+declare class ReadableStream {
+  constructor(
+    underlyingSource: ?UnderlyingSource,
+    queuingStrategy: ?QueuingStrategy,
+  ): void,
+
+  locked: boolean,
+
+  cancel(reason: string): void,
+  getReader(): ReadableStreamReader,
+  pipeThrough(transform: PipeThroughTransformStream, options: ?any): void,
+  pipeTo(dest: WritableStream, options: ?PipeToOptions): Promise<void>,
+  tee(): [ReadableStream, ReadableStream],
+};
+
+declare interface WritableStreamController {
+  error(error: Error): void,
+}
+
+declare interface UnderlyingSink {
+  autoAllocateChunkSize?: number,
+  type?: string,
+
+  abort?: (reason: string) => ?Promise<void>,
+  close?: (controller: WritableStreamController) => ?Promise<void>,
+  start?: (controller: WritableStreamController) => ?Promise<void>,
+  write?: (chunk: any, controller: WritableStreamController) => ?Promise<void>,
+}
+
+declare interface WritableStreamWriter {
+  closed: Promise<any>,
+  desiredSize?: number,
+  ready: Promise<any>,
+
+  abort(reason: string): ?Promise<any>,
+  close(): Promise<any>,
+  releaseLock(): void,
+  write(chunk: any): Promise<any>,
+}
+
+declare class WritableStream {
+  constructor(
+    underlyingSink: ?UnderlyingSink,
+    queuingStrategy: QueuingStrategy,
+  ): void,
+
+  locked: boolean,
+
+  abort(reason: string): void,
+  getWriter(): WritableStreamWriter,
+}