diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4873bea6e279a4663294a0ee2dc517e9cd03acd1..6d3ee52e70e84a3a2cd506b91ad3e72d8b355f0e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -9,6 +9,8 @@ build:
   image: openjdk:8
   stage: build
   script:
+    # see discussion in the answer of https://stackoverflow.com/questions/44911155/gradle-how-to-include-runtimeonly-dependencies-in-javaexec-classpath
+    - ./gradlew --console=plain --no-daemon relast.preprocessor:jar
     - ./gradlew --console=plain --no-daemon assemble jar
   artifacts:
     paths: