diff --git a/build.gradle b/build.gradle
index 831d462..88279c3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,5 +1,7 @@
 apply plugin: 'java'
 
+sourceCompatibility = 11
+
 subprojects.each { subproject ->
   evaluationDependsOn(subproject.path)
 }