diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 55d347f989a395dc7a28430d058a4b558e6b90d6..64870b40f8b51d794b5d035582e206f882ee7d67 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -33,7 +33,7 @@ img_cache:
   stage: singularity
   script:
     - mkdir -p ${dir}cache/
-    - cat nextflow.config | grep -oP "container = \K.*" | tr -d "'" | sort | uniq | xargs -P 5 -I {} singularity pull --dir ${dir} 'docker://'{} || true
+    - cat nextflow.config | grep -oP "container = \K.*" | tr -d "'" | sort | uniq | xargs -P 3 -I {} singularity pull --dir ${dir} 'docker://'{} || true
 
 collect:
   stage: versions