diff --git a/experimental/puppeteer-firefox/lib/Input.js b/experimental/puppeteer-firefox/lib/Input.js
index 11096ca8e27..10bbb401e63 100644
--- a/experimental/puppeteer-firefox/lib/Input.js
+++ b/experimental/puppeteer-firefox/lib/Input.js
@@ -114,9 +114,6 @@ class Keyboard {
     if (this._modifiers & ~8)
       description.text = '';
 
-    // Firefox calls the 'Meta' key 'OS' on everything but mac
-    if (os.platform() !== 'darwin' && description.key === 'Meta')
-      description.key = 'OS';
     if (description.code === 'MetaLeft')
       description.code = 'OSLeft';
     if (description.code === 'MetaRight')
diff --git a/experimental/puppeteer-firefox/package.json b/experimental/puppeteer-firefox/package.json
index a7461aeacb9..335f9d2652c 100644
--- a/experimental/puppeteer-firefox/package.json
+++ b/experimental/puppeteer-firefox/package.json
@@ -9,7 +9,7 @@
     "node": ">=8.9.4"
   },
   "puppeteer": {
-    "firefox_revision": "fd63770c54de8a6e4ac28bd9f010405c12105d63"
+    "firefox_revision": "2f959d575a3d61f5dda12e4e2dca1f46a92ab569"
   },
   "scripts": {
     "install": "node install.js",
diff --git a/test/assets/input/keyboard.html b/test/assets/input/keyboard.html
index 9f1d48152d9..fd962c7518d 100644
--- a/test/assets/input/keyboard.html
+++ b/test/assets/input/keyboard.html
@@ -24,8 +24,6 @@
           m.push('Alt')
         if (event.ctrlKey)
           m.push('Control');
-        if (event.metaKey)
-          m.push('Meta')
         if (event.shiftKey)
           m.push('Shift')
         return '[' + m.join(' ') + ']';
diff --git a/test/keyboard.spec.js b/test/keyboard.spec.js
index aee44bbec20..8ac68143c01 100644
--- a/test/keyboard.spec.js
+++ b/test/keyboard.spec.js
@@ -81,10 +81,10 @@ module.exports.addTests = function({testRunner, expect, FFOX}) {
       await page.keyboard.sendCharacter('a');
       expect(await page.evaluate(() => document.querySelector('textarea').value)).toBe('嗨a');
     });
-    it_fails_ffox('should report shiftKey', async({page, server}) => {
+    it('should report shiftKey', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/keyboard.html');
       const keyboard = page.keyboard;
-      const codeForKey = {'Shift': 16, 'Alt': 18, 'Meta': 91, 'Control': 17};
+      const codeForKey = {'Shift': 16, 'Alt': 18, 'Control': 17};
       for (const modifierKey in codeForKey) {
         await keyboard.down(modifierKey);
         expect(await page.evaluate(() => getResult())).toBe('Keydown: ' + modifierKey + ' ' + modifierKey + 'Left ' + codeForKey[modifierKey] + ' [' + modifierKey + ']');
@@ -101,21 +101,21 @@ module.exports.addTests = function({testRunner, expect, FFOX}) {
         expect(await page.evaluate(() => getResult())).toBe('Keyup: ' + modifierKey + ' ' + modifierKey + 'Left ' + codeForKey[modifierKey] + ' []');
       }
     });
-    it_fails_ffox('should report multiple modifiers', async({page, server}) => {
+    it('should report multiple modifiers', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/keyboard.html');
       const keyboard = page.keyboard;
       await keyboard.down('Control');
       expect(await page.evaluate(() => getResult())).toBe('Keydown: Control ControlLeft 17 [Control]');
-      await keyboard.down('Meta');
-      expect(await page.evaluate(() => getResult())).toBe('Keydown: Meta MetaLeft 91 [Control Meta]');
+      await keyboard.down('Alt');
+      expect(await page.evaluate(() => getResult())).toBe('Keydown: Alt AltLeft 18 [Alt Control]');
       await keyboard.down(';');
-      expect(await page.evaluate(() => getResult())).toBe('Keydown: ; Semicolon 186 [Control Meta]');
+      expect(await page.evaluate(() => getResult())).toBe('Keydown: ; Semicolon 186 [Alt Control]');
       await keyboard.up(';');
-      expect(await page.evaluate(() => getResult())).toBe('Keyup: ; Semicolon 186 [Control Meta]');
+      expect(await page.evaluate(() => getResult())).toBe('Keyup: ; Semicolon 186 [Alt Control]');
       await keyboard.up('Control');
-      expect(await page.evaluate(() => getResult())).toBe('Keyup: Control ControlLeft 17 [Meta]');
-      await keyboard.up('Meta');
-      expect(await page.evaluate(() => getResult())).toBe('Keyup: Meta MetaLeft 91 []');
+      expect(await page.evaluate(() => getResult())).toBe('Keyup: Control ControlLeft 17 [Alt]');
+      await keyboard.up('Alt');
+      expect(await page.evaluate(() => getResult())).toBe('Keyup: Alt AltLeft 18 []');
     });
     it('should send proper codes while typing', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/keyboard.html');
@@ -225,5 +225,30 @@ module.exports.addTests = function({testRunner, expect, FFOX}) {
       await textarea.type('👹 Tokyo street Japan 🇯🇵');
       expect(await frame.$eval('textarea', textarea => textarea.value)).toBe('👹 Tokyo street Japan 🇯🇵');
     });
+    it('should press the meta key', async({page}) => {
+      await page.evaluate(() => {
+        window.result = null;
+        document.addEventListener('keydown', event => {
+          window.result = [event.key, event.code, event.metaKey];
+        });
+      });
+      await page.keyboard.press('Meta');
+      const [key, code, metaKey] = await page.evaluate('result');
+      if (FFOX && os.platform() !== 'darwin')
+        expect(key).toBe('OS');
+      else
+        expect(key).toBe('Meta');
+
+      if (FFOX)
+        expect(code).toBe('OSLeft');
+      else
+        expect(code).toBe('MetaLeft');
+
+      if (FFOX && os.platform() !== 'darwin')
+        expect(metaKey).toBe(false);
+      else
+        expect(metaKey).toBe(true);
+
+    });
   });
 };
diff --git a/test/mouse.spec.js b/test/mouse.spec.js
index 68adf923881..b9d70702beb 100644
--- a/test/mouse.spec.js
+++ b/test/mouse.spec.js
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+const os = require('os');
 
 function dimensions() {
   const rect = document.querySelector('textarea').getBoundingClientRect();
@@ -99,7 +100,7 @@ module.exports.addTests = function({testRunner, expect, FFOX}) {
       await page.hover('#button-6');
       expect(await page.evaluate(() => document.querySelector('button:hover').id)).toBe('button-6');
     });
-    it_fails_ffox('should set modifier keys on click', async({page, server}) => {
+    it('should set modifier keys on click', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/scrollable.html');
       await page.evaluate(() => document.querySelector('#button-3').addEventListener('mousedown', e => window.lastEvent = e, true));
       const modifiers = {'Shift': 'shiftKey', 'Control': 'ctrlKey', 'Alt': 'altKey', 'Meta': 'metaKey'};