diff --git a/android-interop-testing/build.gradle b/android-interop-testing/build.gradle
index 91e75fcfad8..7cefa2ea28a 100644
--- a/android-interop-testing/build.gradle
+++ b/android-interop-testing/build.gradle
@@ -25,6 +25,10 @@ android {
             }
         }
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
     compileSdkVersion 26
 
     defaultConfig {
diff --git a/android/build.gradle b/android/build.gradle
index 1fa8fbad937..0f802a66606 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -8,6 +8,10 @@ plugins {
 description = 'gRPC: Android'
 
 android {
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
     compileSdkVersion 29
     defaultConfig {
         consumerProguardFiles "proguard-rules.txt"
diff --git a/build.gradle b/build.gradle
index 56d28697f5e..36ccf753e0f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -55,7 +55,7 @@ subprojects {
         javaPluginPath = "$rootDir/compiler/build/exe/java_plugin/$protocPluginBaseName$exeSuffix"
 
         nettyVersion = '4.1.52.Final'
-        guavaVersion = '30.0-android'
+        guavaVersion = '30.1-android'
         googleauthVersion = '0.22.2'
         protobufVersion = '3.12.0'
         protocVersion = protobufVersion
diff --git a/examples/android/clientcache/app/build.gradle b/examples/android/clientcache/app/build.gradle
index 91eb289cb0a..b13afd88411 100644
--- a/examples/android/clientcache/app/build.gradle
+++ b/examples/android/clientcache/app/build.gradle
@@ -2,6 +2,10 @@ apply plugin: 'com.android.application'
 apply plugin: 'com.google.protobuf'
 
 android {
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
     compileSdkVersion 27
 
     defaultConfig {
diff --git a/examples/android/helloworld/app/build.gradle b/examples/android/helloworld/app/build.gradle
index 057b27e8bb3..24351d62439 100644
--- a/examples/android/helloworld/app/build.gradle
+++ b/examples/android/helloworld/app/build.gradle
@@ -2,6 +2,10 @@ apply plugin: 'com.android.application'
 apply plugin: 'com.google.protobuf'
 
 android {
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
     compileSdkVersion 27
 
     defaultConfig {
diff --git a/examples/android/routeguide/app/build.gradle b/examples/android/routeguide/app/build.gradle
index 83b8b97ec04..e01287c6098 100644
--- a/examples/android/routeguide/app/build.gradle
+++ b/examples/android/routeguide/app/build.gradle
@@ -2,6 +2,10 @@ apply plugin: 'com.android.application'
 apply plugin: 'com.google.protobuf'
 
 android {
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
     compileSdkVersion 27
 
     defaultConfig {
diff --git a/examples/android/strictmode/app/build.gradle b/examples/android/strictmode/app/build.gradle
index b6cd8f11e96..552b5a3bb90 100644
--- a/examples/android/strictmode/app/build.gradle
+++ b/examples/android/strictmode/app/build.gradle
@@ -2,6 +2,10 @@ apply plugin: 'com.android.application'
 apply plugin: 'com.google.protobuf'
 
 android {
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
     compileSdkVersion 28
 
     defaultConfig {