diff --git a/build.gradle b/build.gradle
index f7cc885..9199bbf 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,6 +6,8 @@ plugins {
 group 'uk.ac.hutton.ics'
 version '1.0.1'
 
+sourceCompatibility = 1.8
+
 repositories {
     jcenter()
     mavenCentral()