diff --git a/reana/reana_dev/cluster.py b/reana/reana_dev/cluster.py
index 6e538e02..c6628b49 100644
--- a/reana/reana_dev/cluster.py
+++ b/reana/reana_dev/cluster.py
@@ -367,7 +367,8 @@ def job_mounts_to_config(job_mounts):
                 "enabled"
             ] = False
 
-    values_yaml = yaml.dump(values_dict) if values_dict else ""
+    # set arbitrary big value for `width` to prevent PyYAML from wrapping long lines
+    values_yaml = yaml.dump(values_dict, width=100000) if values_dict else ""
     helm_install = f"cat <<EOF | helm install {instance_name} helm/reana -n {namespace} --create-namespace --wait -f -\n{values_yaml}\nEOF"
 
     cmds = []