diff --git a/sources/build.gradle b/sources/build.gradle
index e0296465..c77bdc60 100644
--- a/sources/build.gradle
+++ b/sources/build.gradle
@@ -161,6 +161,7 @@ test {
 }
 
 dependencies {
+    compile 'ch.qos.logback:logback-classic:1.2.3'
     compile 'com.google.code.gson:gson:2.8.0'
     compile 'org.slf4j:slf4j-api:1.7.7'
     compile 'org.apache.httpcomponents:httpclient:4.5.3'