diff --git a/java/build.gradle b/java/build.gradle
index 5d1b4d9..4bd8921 100644
--- a/java/build.gradle
+++ b/java/build.gradle
@@ -7,6 +7,8 @@ apply plugin: 'bintray-release'
 
 dependencies {
     testCompile 'junit:junit:4.12'
+    sourceCompatibility = 1.7
+    targetCompatibility = 1.7
 }
 
 publish {