diff --git a/lib/galaxy/jobs/runners/kubernetes.py b/lib/galaxy/jobs/runners/kubernetes.py
index f70ab7619aa..b638e56b4e2 100644
--- a/lib/galaxy/jobs/runners/kubernetes.py
+++ b/lib/galaxy/jobs/runners/kubernetes.py
@@ -57,7 +57,7 @@ class KubernetesJobRunner(AsynchronousJobRunner):
             k8s_default_requests_memory=dict(map=str, default=None),
             k8s_default_limits_cpu=dict(map=str, default=None),
             k8s_default_limits_memory=dict(map=str, default=None),
-            k8s_cleanup_job=dict(map=str, valid=lambda s: s in set(["onsuccess", "always", "never"]), default="always"),
+            k8s_cleanup_job=dict(map=str, valid=lambda s: s in {"onsuccess", "always", "never"}, default="always"),
             k8s_pod_retries=dict(map=int, valid=lambda x: int >= 0, default=3),
             k8s_pod_retrials=dict(map=int, valid=lambda x: int >= 0, default=3),
             k8s_walltime_limit=dict(map=int, valid=lambda x: int(x) >= 0, default=172800))