diff --git a/docs/api.md b/docs/api.md
index c4f0d5dd0a..ef2284f67a 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -1138,8 +1138,8 @@ await page.dispatchEvent('#source', 'dragstart', { dataTransfer });
 
 #### page.emulateMedia(options)
 - `options` <[Object]>
-  - `media` <"screen"|"print"> Changes the CSS media type of the page. The only allowed values are `'screen'`, `'print'` and `null`. Passing `null` disables CSS media emulation.
-  - `colorScheme` <"dark"|"light"|"no-preference"> Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`.
+  - `media` <?"screen"|"print"> Changes the CSS media type of the page. The only allowed values are `'screen'`, `'print'` and `null`. Passing `null` disables CSS media emulation. Omitting `media` or passing `undefined` does not change the emulated value.
+  - `colorScheme` <?"dark"|"light"|"no-preference"> Emulates `'prefers-colors-scheme'` media feature, supported values are `'light'`, `'dark'`, `'no-preference'`. Passing `null` disables color scheme emulation. Omitting `colorScheme` or passing `undefined` does not change the emulated value.
 - returns: <[Promise]>
 
 ```js
diff --git a/src/firefox/ffPage.ts b/src/firefox/ffPage.ts
index 4855609745..142717a6d1 100644
--- a/src/firefox/ffPage.ts
+++ b/src/firefox/ffPage.ts
@@ -293,7 +293,8 @@ export class FFPage implements PageDelegate {
   async updateEmulateMedia(): Promise<void> {
     const colorScheme = this._page._state.colorScheme || this._browserContext._options.colorScheme || 'light';
     await this._session.send('Page.setEmulatedMedia', {
-      type: this._page._state.mediaType === null ? undefined : this._page._state.mediaType,
+      // Empty string means reset.
+      type: this._page._state.mediaType === null ? '' : this._page._state.mediaType,
       colorScheme
     });
   }
diff --git a/src/page.ts b/src/page.ts
index 8442fadfec..ff4ba7acd5 100644
--- a/src/page.ts
+++ b/src/page.ts
@@ -385,9 +385,11 @@ export class Page extends EventEmitter {
     return waitPromise;
   }
 
-  async emulateMedia(options: { media?: types.MediaType, colorScheme?: types.ColorScheme }) {
-    assert(!options.media || types.mediaTypes.has(options.media), 'media: expected one of (screen|print)');
-    assert(!options.colorScheme || types.colorSchemes.has(options.colorScheme), 'colorScheme: expected one of (dark|light|no-preference)');
+  async emulateMedia(options: { media?: types.MediaType | null, colorScheme?: types.ColorScheme | null }) {
+    if (options.media !== undefined)
+      assert(options.media === null || types.mediaTypes.has(options.media), 'media: expected one of (screen|print)');
+    if (options.colorScheme !== undefined)
+      assert(options.colorScheme === null || types.colorSchemes.has(options.colorScheme), 'colorScheme: expected one of (dark|light|no-preference)');
     if (options.media !== undefined)
       this._state.mediaType = options.media;
     if (options.colorScheme !== undefined)
diff --git a/src/rpc/channels.ts b/src/rpc/channels.ts
index ffa32805a0..310622f747 100644
--- a/src/rpc/channels.ts
+++ b/src/rpc/channels.ts
@@ -618,8 +618,8 @@ export type PageCloseParams = {
 };
 export type PageCloseResult = void;
 export type PageEmulateMediaParams = {
-  media?: 'screen' | 'print',
-  colorScheme?: 'dark' | 'light' | 'no-preference',
+  media?: 'screen' | 'print' | 'reset',
+  colorScheme?: 'dark' | 'light' | 'no-preference' | 'reset',
 };
 export type PageEmulateMediaResult = void;
 export type PageExposeBindingParams = {
diff --git a/src/rpc/client/page.ts b/src/rpc/client/page.ts
index dce4f1983f..c6d15d81da 100644
--- a/src/rpc/client/page.ts
+++ b/src/rpc/client/page.ts
@@ -357,9 +357,12 @@ export class Page extends ChannelOwner<PageChannel, PageInitializer> {
     });
   }
 
-  async emulateMedia(options: { media?: types.MediaType, colorScheme?: types.ColorScheme }) {
+  async emulateMedia(options: { media?: types.MediaType | null, colorScheme?: types.ColorScheme | null }) {
     return this._wrapApiCall('page.emulateMedia', async () => {
-      await this._channel.emulateMedia(options);
+      await this._channel.emulateMedia({
+        media: options.media === null ? 'reset' : options.media,
+        colorScheme: options.colorScheme === null ? 'reset' : options.colorScheme,
+      });
     });
   }
 
diff --git a/src/rpc/protocol.pdl b/src/rpc/protocol.pdl
index 83e9d774b0..4b0d375ff6 100644
--- a/src/rpc/protocol.pdl
+++ b/src/rpc/protocol.pdl
@@ -527,10 +527,14 @@ interface Page
       media?: enum
         screen
         print
+        # Reset emulated value to the system default.
+        reset
       colorScheme?: enum
         dark
         light
         no-preference
+        # Reset emulated value to the system default.
+        reset
 
   command exposeBinding
     parameters
diff --git a/src/rpc/server/pageDispatcher.ts b/src/rpc/server/pageDispatcher.ts
index 5b10fa8b9f..5d132812cc 100644
--- a/src/rpc/server/pageDispatcher.ts
+++ b/src/rpc/server/pageDispatcher.ts
@@ -20,7 +20,7 @@ import { Frame } from '../../frames';
 import { Request } from '../../network';
 import { Page, Worker } from '../../page';
 import * as types from '../../types';
-import { BindingCallChannel, BindingCallInitializer, ElementHandleChannel, PageChannel, PageInitializer, ResponseChannel, WorkerInitializer, WorkerChannel, JSHandleChannel, Binary, SerializedArgument, PagePdfParams, SerializedError, PageAccessibilitySnapshotResult, SerializedValue } from '../channels';
+import { BindingCallChannel, BindingCallInitializer, ElementHandleChannel, PageChannel, PageInitializer, ResponseChannel, WorkerInitializer, WorkerChannel, JSHandleChannel, Binary, SerializedArgument, PagePdfParams, SerializedError, PageAccessibilitySnapshotResult, SerializedValue, PageEmulateMediaParams } from '../channels';
 import { Dispatcher, DispatcherScope, lookupDispatcher, lookupNullableDispatcher } from './dispatcher';
 import { parseError, serializeError, headersArrayToObject, axNodeToProtocol } from '../serializers';
 import { ConsoleMessageDispatcher } from './consoleMessageDispatcher';
@@ -106,8 +106,11 @@ export class PageDispatcher extends Dispatcher<Page, PageInitializer> implements
     return { response: lookupNullableDispatcher<ResponseDispatcher>(await this._page.goForward(params)) };
   }
 
-  async emulateMedia(params: { media?: 'screen' | 'print', colorScheme?: 'dark' | 'light' | 'no-preference' }): Promise<void> {
-    await this._page.emulateMedia(params);
+  async emulateMedia(params: PageEmulateMediaParams): Promise<void> {
+    await this._page.emulateMedia({
+      media: params.media === 'reset' ? null : params.media,
+      colorScheme: params.colorScheme === 'reset' ? null : params.colorScheme,
+    });
   }
 
   async setViewportSize(params: { viewportSize: types.Size }): Promise<void> {
diff --git a/test/emulation.jest.js b/test/emulation.jest.js
index 33c6bd3a28..75eebd8443 100644
--- a/test/emulation.jest.js
+++ b/test/emulation.jest.js
@@ -241,7 +241,7 @@ describe('Page.emulateMedia type', function() {
     await page.emulateMedia({});
     expect(await page.evaluate(() => matchMedia('screen').matches)).toBe(false);
     expect(await page.evaluate(() => matchMedia('print').matches)).toBe(true);
-    await page.emulateMedia({ media: '' });
+    await page.emulateMedia({ media: null });
     expect(await page.evaluate(() => matchMedia('screen').matches)).toBe(true);
     expect(await page.evaluate(() => matchMedia('print').matches)).toBe(false);
   });