diff --git a/constants.gradle b/constants.gradle
index b0a0e4fce5..852da69b07 100644
--- a/constants.gradle
+++ b/constants.gradle
@@ -31,6 +31,7 @@ project.ext {
     androidxAppCompatVersion = '1.1.0'
     androidxCollectionVersion = '1.1.0'
     androidxMediaVersion = '1.0.1'
+    androidxMultidexVersion = '2.0.0'
     androidxTestCoreVersion = '1.2.0'
     androidxTestJUnitVersion = '1.1.1'
     androidxTestRunnerVersion = '1.2.0'
diff --git a/demos/cast/build.gradle b/demos/cast/build.gradle
index c929f09c87..b26112e15a 100644
--- a/demos/cast/build.gradle
+++ b/demos/cast/build.gradle
@@ -27,6 +27,7 @@ android {
         versionCode project.ext.releaseVersionCode
         minSdkVersion project.ext.minSdkVersion
         targetSdkVersion project.ext.appTargetSdkVersion
+        multiDexEnabled true
     }
 
     buildTypes {
@@ -57,6 +58,7 @@ dependencies {
     implementation project(modulePrefix + 'library-ui')
     implementation project(modulePrefix + 'extension-cast')
     implementation 'androidx.appcompat:appcompat:' + androidxAppCompatVersion
+    implementation 'androidx.multidex:multidex:' + androidxMultidexVersion
     implementation 'androidx.recyclerview:recyclerview:1.1.0'
     implementation 'com.google.android.material:material:1.1.0'
 }
diff --git a/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/DemoApplication.java b/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/DemoApplication.java
new file mode 100644
index 0000000000..f2d2288b6a
--- /dev/null
+++ b/demos/cast/src/main/java/com/google/android/exoplayer2/castdemo/DemoApplication.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.castdemo;
+
+import androidx.multidex.MultiDexApplication;
+
+// Note: Multidex is enabled in code not AndroidManifest.xml because the internal build system
+// doesn't dejetify MultiDexApplication in AndroidManifest.xml.
+/** Application for multidex support. */
+public final class DemoApplication extends MultiDexApplication {}
diff --git a/demos/main/build.gradle b/demos/main/build.gradle
index b7a8666fe3..f26fd7dc32 100644
--- a/demos/main/build.gradle
+++ b/demos/main/build.gradle
@@ -27,6 +27,7 @@ android {
         versionCode project.ext.releaseVersionCode
         minSdkVersion project.ext.minSdkVersion
         targetSdkVersion project.ext.appTargetSdkVersion
+        multiDexEnabled true
     }
 
     buildTypes {
@@ -64,6 +65,7 @@ android {
 dependencies {
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
     implementation 'androidx.appcompat:appcompat:' + androidxAppCompatVersion
+    implementation 'androidx.multidex:multidex:' + androidxMultidexVersion
     implementation 'com.google.android.material:material:1.1.0'
     implementation project(modulePrefix + 'library-core')
     implementation project(modulePrefix + 'library-dash')
diff --git a/demos/main/src/main/java/com/google/android/exoplayer2/demo/DemoApplication.java b/demos/main/src/main/java/com/google/android/exoplayer2/demo/DemoApplication.java
index c36d370992..86978a1613 100644
--- a/demos/main/src/main/java/com/google/android/exoplayer2/demo/DemoApplication.java
+++ b/demos/main/src/main/java/com/google/android/exoplayer2/demo/DemoApplication.java
@@ -15,7 +15,7 @@
  */
 package com.google.android.exoplayer2.demo;
 
-import android.app.Application;
+import androidx.multidex.MultiDexApplication;
 import com.google.android.exoplayer2.DefaultRenderersFactory;
 import com.google.android.exoplayer2.RenderersFactory;
 import com.google.android.exoplayer2.database.DatabaseProvider;
@@ -40,7 +40,7 @@ import java.io.IOException;
 /**
  * Placeholder application to facilitate overriding Application methods for debugging and testing.
  */
-public class DemoApplication extends Application {
+public class DemoApplication extends MultiDexApplication {
 
   public static final String DOWNLOAD_NOTIFICATION_CHANNEL_ID = "download_channel";
 
diff --git a/extensions/ima/build.gradle b/extensions/ima/build.gradle
index f25a26b3a9..28f201e24b 100644
--- a/extensions/ima/build.gradle
+++ b/extensions/ima/build.gradle
@@ -45,9 +45,9 @@ dependencies {
     implementation 'com.google.android.gms:play-services-ads-identifier:17.0.0'
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion
     androidTestImplementation project(modulePrefix + 'testutils')
+    androidTestImplementation 'androidx.multidex:multidex:' + androidxMultidexVersion
     androidTestImplementation 'androidx.test:rules:' + androidxTestRulesVersion
     androidTestImplementation 'androidx.test:runner:' + androidxTestRunnerVersion
-    androidTestImplementation 'com.android.support:multidex:1.0.3'
     androidTestCompileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     testImplementation project(modulePrefix + 'testutils')
     testImplementation 'com.google.guava:guava:' + guavaVersion