diff --git a/Server-Protocol-Buffer/build.gradle b/Server-Protocol-Buffer/build.gradle
index fa9743f3fc4e4b6839b18435c4e0a6e0a89cfdc8..63f5ce8d7e13cc6dd26e61cd529737afa9c1d439 100644
--- a/Server-Protocol-Buffer/build.gradle
+++ b/Server-Protocol-Buffer/build.gradle
@@ -5,6 +5,9 @@ sourceSets {
     main.java.srcDirs += "${protobuf.generatedFilesBaseDir}/main/javalite"
 }
 
+sourceCompatibility = "8"
+targetCompatibility = "8"
+
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     api 'com.google.protobuf:protobuf-lite:3.0.1'