diff --git a/app/src/androidTest/java/org/mozilla/fenix/glean/BaselinePingTest.kt b/app/src/androidTest/java/org/mozilla/fenix/glean/BaselinePingTest.kt
index 1199adf35..afcc8d50e 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/glean/BaselinePingTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/glean/BaselinePingTest.kt
@@ -110,7 +110,7 @@ class BaselinePingTest {
         do {
             attempts += 1
             val request = server.takeRequest(20L, TimeUnit.SECONDS) ?: break
-            val docType = request.path.split("/")[3]
+            val docType = request.path!!.split("/")[3]
             if (pingName == docType) {
                 val parsedPayload = JSONObject(request.getPlainBody())
                 if (pingReason == null) {
diff --git a/app/src/androidTest/java/org/mozilla/fenix/helpers/MockWebServer.kt b/app/src/androidTest/java/org/mozilla/fenix/helpers/MockWebServer.kt
index 5dfc98ec8..5bbc5f318 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/helpers/MockWebServer.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/helpers/MockWebServer.kt
@@ -39,11 +39,13 @@ object MockWebServerHelper {
      */
     fun createAlwaysOkMockWebServer(): MockWebServer {
         return MockWebServer().apply {
-            setDispatcher(object : Dispatcher() {
+            val dispatcher = object : Dispatcher() {
+                @Throws(InterruptedException::class)
                 override fun dispatch(request: RecordedRequest): MockResponse {
                     return MockResponse().setBody("OK")
                 }
-            })
+            }
+            this.dispatcher = dispatcher
         }
     }
 }
@@ -62,10 +64,10 @@ const val HTTP_NOT_FOUND = 404
 class AndroidAssetDispatcher : Dispatcher() {
     private val mainThreadHandler = Handler(Looper.getMainLooper())
 
-    override fun dispatch(request: RecordedRequest?): MockResponse {
+    override fun dispatch(request: RecordedRequest): MockResponse {
         val assetManager = InstrumentationRegistry.getInstrumentation().context.assets
         try {
-            val pathWithoutQueryParams = Uri.parse(request?.path?.drop(1)).path
+            val pathWithoutQueryParams = Uri.parse(request.path!!.drop(1)).path
             assetManager.open(pathWithoutQueryParams!!).use { inputStream ->
                 return fileToResponse(pathWithoutQueryParams, inputStream)
             }
@@ -81,7 +83,7 @@ class AndroidAssetDispatcher : Dispatcher() {
 private fun fileToResponse(path: String, file: InputStream): MockResponse {
     return MockResponse()
         .setResponseCode(HTTP_OK)
-        .setBody(fileToBytes(file))
+        .setBody(fileToBytes(file)!!)
         .addHeader("content-type: " + contentType(path))
 }
 
diff --git a/app/src/androidTest/java/org/mozilla/fenix/screenshots/MenuScreenShotTest.kt b/app/src/androidTest/java/org/mozilla/fenix/screenshots/MenuScreenShotTest.kt
index c6e1e5951..3e3f2d674 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/screenshots/MenuScreenShotTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/screenshots/MenuScreenShotTest.kt
@@ -43,7 +43,7 @@ class MenuScreenShotTest : ScreenshotTest() {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/syncintegration/SyncIntegrationTest.kt b/app/src/androidTest/java/org/mozilla/fenix/syncintegration/SyncIntegrationTest.kt
index 283a46e05..7b6c02d16 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/syncintegration/SyncIntegrationTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/syncintegration/SyncIntegrationTest.kt
@@ -44,7 +44,7 @@ class SyncIntegrationTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/BookmarksTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/BookmarksTest.kt
index ddcdd7c84..59e08ac3b 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/BookmarksTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/BookmarksTest.kt
@@ -49,7 +49,7 @@ class BookmarksTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/ContextMenusTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/ContextMenusTest.kt
index 67125a717..c877171ec 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/ContextMenusTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/ContextMenusTest.kt
@@ -42,7 +42,7 @@ class ContextMenusTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/DeepLinkTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/DeepLinkTest.kt
index 4f9a0885e..7bca26ebe 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/DeepLinkTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/DeepLinkTest.kt
@@ -43,7 +43,7 @@ class DeepLinkTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/DownloadTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/DownloadTest.kt
index cef6dbeb2..c0919cce8 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/DownloadTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/DownloadTest.kt
@@ -51,7 +51,7 @@ class DownloadTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/HistoryTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/HistoryTest.kt
index 19f97ddcb..fcca0e9de 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/HistoryTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/HistoryTest.kt
@@ -41,7 +41,7 @@ class HistoryTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/MediaNotificationTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/MediaNotificationTest.kt
index 5f3baff90..02ce669f2 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/MediaNotificationTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/MediaNotificationTest.kt
@@ -37,7 +37,7 @@ class MediaNotificationTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/NavigationToolbarTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/NavigationToolbarTest.kt
index 65e850860..ae9c165e6 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/NavigationToolbarTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/NavigationToolbarTest.kt
@@ -38,7 +38,7 @@ class NavigationToolbarTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/ReaderViewTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/ReaderViewTest.kt
index 4e08cbc41..e73ac0182 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/ReaderViewTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/ReaderViewTest.kt
@@ -41,7 +41,7 @@ class ReaderViewTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
 
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAboutTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAboutTest.kt
index 26368bd0a..ba101f0c9 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAboutTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAboutTest.kt
@@ -33,7 +33,7 @@ class SettingsAboutTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAddonsTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAddonsTest.kt
index 12b74d038..79057f88c 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAddonsTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAddonsTest.kt
@@ -39,7 +39,7 @@ class SettingsAddonsTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAdvancedTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAdvancedTest.kt
index 381cc9862..c12669080 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAdvancedTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAdvancedTest.kt
@@ -32,7 +32,7 @@ class SettingsAdvancedTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsBasicsTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsBasicsTest.kt
index 3e43e80b7..9efc25ab8 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsBasicsTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsBasicsTest.kt
@@ -39,7 +39,7 @@ class SettingsBasicsTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsDeveloperToolsTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsDeveloperToolsTest.kt
index f42902c99..c7cfed81f 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsDeveloperToolsTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsDeveloperToolsTest.kt
@@ -33,7 +33,7 @@ class SettingsDeveloperToolsTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsPrivacyTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsPrivacyTest.kt
index 78802cda9..0c2bbba58 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsPrivacyTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsPrivacyTest.kt
@@ -41,7 +41,7 @@ class SettingsPrivacyTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsSyncTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsSyncTest.kt
index 21ce9cf77..55bd79651 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsSyncTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsSyncTest.kt
@@ -32,7 +32,7 @@ class SettingsSyncTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsTest.kt
index ebb66370a..2672d1afd 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsTest.kt
@@ -32,7 +32,7 @@ class SettingsTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/ShareButtonTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/ShareButtonTest.kt
index f8f942035..bc9767cdb 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/ShareButtonTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/ShareButtonTest.kt
@@ -33,7 +33,7 @@ class ShareButtonTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/SmokeTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/SmokeTest.kt
index 695fac0d0..d4f64ef4b 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/SmokeTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/SmokeTest.kt
@@ -34,7 +34,7 @@ class SmokeTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/StrictEnhancedTrackingProtectionTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/StrictEnhancedTrackingProtectionTest.kt
index 86f5c929f..659f7547e 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/StrictEnhancedTrackingProtectionTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/StrictEnhancedTrackingProtectionTest.kt
@@ -42,7 +42,7 @@ class StrictEnhancedTrackingProtectionTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
 
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/TabbedBrowsingTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/TabbedBrowsingTest.kt
index bebecaba5..a946cfb78 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/TabbedBrowsingTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/TabbedBrowsingTest.kt
@@ -49,7 +49,7 @@ class TabbedBrowsingTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/ThreeDotMenuMainTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/ThreeDotMenuMainTest.kt
index 59e392a06..0de072569 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/ThreeDotMenuMainTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/ThreeDotMenuMainTest.kt
@@ -32,7 +32,7 @@ class ThreeDotMenuMainTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/app/src/androidTest/java/org/mozilla/fenix/ui/TopSitesTest.kt b/app/src/androidTest/java/org/mozilla/fenix/ui/TopSitesTest.kt
index 674e767c2..65cb25b59 100644
--- a/app/src/androidTest/java/org/mozilla/fenix/ui/TopSitesTest.kt
+++ b/app/src/androidTest/java/org/mozilla/fenix/ui/TopSitesTest.kt
@@ -36,7 +36,7 @@ class TopSitesTest {
     @Before
     fun setUp() {
         mockWebServer = MockWebServer().apply {
-            setDispatcher(AndroidAssetDispatcher())
+            dispatcher = AndroidAssetDispatcher()
             start()
         }
     }
diff --git a/buildSrc/src/main/java/Dependencies.kt b/buildSrc/src/main/java/Dependencies.kt
index 67c256090..f30f5c691 100644
--- a/buildSrc/src/main/java/Dependencies.kt
+++ b/buildSrc/src/main/java/Dependencies.kt
@@ -43,7 +43,7 @@ object Versions {
     const val junit = "5.5.2"
     const val mockk = "1.10.0"
 
-    const val mockwebserver = "3.11.0"
+    const val mockwebserver = "4.9.0"
     const val uiautomator = "2.2.0"
 
     const val google_ads_id_version = "16.0.0"