diff --git a/zuul.d/ironic-jobs.yaml b/zuul.d/ironic-jobs.yaml
index 79939f7568..843061a470 100644
--- a/zuul.d/ironic-jobs.yaml
+++ b/zuul.d/ironic-jobs.yaml
@@ -390,7 +390,7 @@
       - zuul: opendev.org/zuul/zuul-jobs
     vars:
       tox_envlist: all
-      tempest_concurrency: 4
+      tempest_concurrency: 3
       tempest_test_regex: "(ironic_tempest_plugin.tests.scenario|test_schedule_to_all_nodes)"
       tempest_test_timeout: 2400
       devstack_localrc:
@@ -421,7 +421,7 @@
         IRONIC_TEMPEST_BUILD_TIMEOUT: 600
         IRONIC_TEMPEST_WHOLE_DISK_IMAGE: True
         IRONIC_USE_LINK_LOCAL: True
-        IRONIC_VM_COUNT: 7
+        IRONIC_VM_COUNT: 6
         IRONIC_VM_EPHEMERAL_DISK: 0
         IRONIC_VM_LOG_DIR: '{{ devstack_base_dir }}/ironic-bm-logs'
         IRONIC_VM_SPECS_RAM: 384
@@ -497,7 +497,7 @@
           IRONIC_PROVISION_NETWORK_NAME: ironic-provision
           IRONIC_RAMDISK_TYPE: tinyipa
           IRONIC_USE_LINK_LOCAL: True
-          IRONIC_VM_COUNT: 7
+          IRONIC_VM_COUNT: 6
           IRONIC_VM_EPHEMERAL_DISK: 0
           IRONIC_VM_LOG_DIR: '{{ devstack_base_dir }}/ironic-bm-logs'
           IRONIC_VM_NETWORK_BRIDGE: sub1brbm