diff --git a/docs/api.md b/docs/api.md
index 9b3c0e4fba..7431627b6d 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -190,7 +190,7 @@ Indicates that the browser is connected.
     - `width` <[number]> page width in pixels.
     - `height` <[number]> page height in pixels.
     - `deviceScaleFactor` <[number]> Specify device scale factor (can be thought of as dpr). Defaults to `1`.
-    - `isMobile` <[boolean]> Whether the `meta viewport` tag is taken into account. Defaults to `false`.
+    - `isMobile` <[boolean]> Whether the `meta viewport` tag is taken into account and touch events are enabled. Defaults to `false`. Not supported in Firefox.
   - `userAgent` <?[string]> Specific user agent to use in this context.
   - `javaScriptEnabled` <?[boolean]> Whether or not to enable or disable JavaScript in the context. Defaults to true.
   - `timezoneId` <?[string]> Changes the timezone of the context. See [ICU’s `metaZones.txt`](https://cs.chromium.org/chromium/src/third_party/icu/source/data/misc/metaZones.txt?rcl=faee8bc70570192d82d2978a71e2a615788597d1) for a list of supported timezone IDs.
@@ -224,7 +224,7 @@ Creates a new browser context. It won't share cookies/cache with other browser c
     - `width` <[number]> page width in pixels.
     - `height` <[number]> page height in pixels.
     - `deviceScaleFactor` <[number]> Specify device scale factor (can be thought of as dpr). Defaults to `1`.
-    - `isMobile` <[boolean]> Whether the `meta viewport` tag is taken into account. Defaults to `false`.
+    - `isMobile` <[boolean]> Whether the `meta viewport` tag is taken into account and touch events are enabled. Defaults to `false`. Not supported in Firefox.
   - `userAgent` <?[string]> Specific user agent to use in this context.
   - `javaScriptEnabled` <?[boolean]> Whether or not to enable or disable JavaScript in the context. Defaults to true.
   - `timezoneId` <?[string]> Changes the timezone of the context. See [ICU’s `metaZones.txt`](https://cs.chromium.org/chromium/src/third_party/icu/source/data/misc/metaZones.txt?rcl=faee8bc70570192d82d2978a71e2a615788597d1) for a list of supported timezone IDs.
diff --git a/src/firefox/ffBrowser.ts b/src/firefox/ffBrowser.ts
index 059dca2f6c..335a35526c 100644
--- a/src/firefox/ffBrowser.ts
+++ b/src/firefox/ffBrowser.ts
@@ -72,17 +72,20 @@ export class FFBrowser extends platform.EventEmitter implements Browser {
     options = validateBrowserContextOptions(options);
     let viewport;
     if (options.viewport) {
+      // TODO: remove isMobile/hasTouch from the protocol?
+      if (options.viewport.isMobile)
+        throw new Error('viewport.isMobile is not supported in Firefox');
       viewport = {
         viewportSize: { width: options.viewport.width, height: options.viewport.height },
-        isMobile: !!options.viewport.isMobile,
         deviceScaleFactor: options.viewport.deviceScaleFactor || 1,
-        hasTouch: !!options.viewport.isMobile,
+        isMobile: false,
+        hasTouch: false,
       };
     } else if (options.viewport !== null) {
       viewport = {
         viewportSize: { width: 1280, height: 720 },
-        isMobile: false,
         deviceScaleFactor: 1,
+        isMobile: false,
         hasTouch: false,
       };
     }
diff --git a/test/mouse.spec.js b/test/mouse.spec.js
index ea53b03bf9..e9de987758 100644
--- a/test/mouse.spec.js
+++ b/test/mouse.spec.js
@@ -132,8 +132,8 @@ module.exports.describe = function({testRunner, expect, FFOX, CHROMIUM, WEBKIT,
         [200, 300]
       ]);
     });
-    // @see https://crbug.com/929806
-    it('should work with mobile viewports and cross process navigations', async({browser, server}) => {
+    it.skip(FFOX)('should work with mobile viewports and cross process navigations', async({browser, server}) => {
+      // @see https://crbug.com/929806
       const context = await browser.newContext({ viewport: {width: 360, height: 640, isMobile: true} });
       const page = await context.newPage();
       await page.goto(server.EMPTY_PAGE);
diff --git a/test/popup.spec.js b/test/popup.spec.js
index 419b61858f..3e7ce606d2 100644
--- a/test/popup.spec.js
+++ b/test/popup.spec.js
@@ -48,7 +48,7 @@ module.exports.describe = function({testRunner, expect, playwright, CHROMIUM, WE
       await context.close();
       expect(request.headers['foo']).toBe('bar');
     });
-    it.fail(CHROMIUM)('should inherit touch support from browser context', async function({browser, server}) {
+    it.skip(FFOX).fail(CHROMIUM)('should inherit touch support from browser context', async function({browser, server}) {
       const context = await browser.newContext({
         viewport: { width: 400, height: 500, isMobile: true }
       });
@@ -61,7 +61,7 @@ module.exports.describe = function({testRunner, expect, playwright, CHROMIUM, WE
       await context.close();
       expect(hasTouch).toBe(true);
     });
-    it.skip(FFOX).fail(CHROMIUM)('should inherit viewport size from browser context', async function({browser, server}) {
+    it.fail(CHROMIUM)('should inherit viewport size from browser context', async function({browser, server}) {
       const context = await browser.newContext({
         viewport: { width: 400, height: 500 }
       });