diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index cd336c03d0ea33734814fbb2f5d0ce558d71ce7e..513111bc0dddadc76ed39a82f752e7a05727d0a8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -27,7 +27,8 @@ test-html:
   image: docker-registry.apertis.org/apertis/apertis-v2020-documentation-builder
   stage: generate-pdf
   script:
-  - find public -name "*.pdf-in" -exec scripts/create-pdf {} \;
+  - echo "Building PDFs on $(nproc) cores"
+  - find public -name "*.pdf-in" -print0 | xargs -0 -r -n1 -P "$(nproc)" scripts/create-pdf
   needs:
   - job: test-html
   artifacts: