diff --git a/backend/build.gradle b/backend/build.gradle
index fb41a137c..47dab440a 100644
--- a/backend/build.gradle
+++ b/backend/build.gradle
@@ -1,5 +1,4 @@
 plugins {
-    id 'java'
     id 'groovy'
     id 'war'
     id 'org.springframework.boot' version '2.0.0.RELEASE'
@@ -114,8 +113,11 @@ def generatedSrcDir = new File(buildDir, 'generated/src/main/java')
 
 sourceSets {
     main {
+        groovy {
+            srcDirs = ['src/main/groovy', 'src/main/java', generatedSrcDir]
+        }
         java {
-            srcDirs += generatedSrcDir
+            srcDirs = []
         }
     }
 }