diff --git a/roles/run-tempest/tasks/main.yaml b/roles/run-tempest/tasks/main.yaml
index 24bd4db..8686f9a 100644
--- a/roles/run-tempest/tasks/main.yaml
+++ b/roles/run-tempest/tasks/main.yaml
@@ -20,6 +20,21 @@
     default_concurrency: "{{ num_cores|int // 2 }}"
   when: num_cores|int > 3
 
+- name: Override target branch
+  set_fact:
+    target_branch: "{{ zuul.override_checkout }}"
+  when: zuul.override_checkout is defined
+
+- name: Use stable branch upper-constraints till stable/rocky
+  set_fact:
+    tempest_tox_environment: "{{ tempest_tox_environment | combine({'UPPER_CONSTRAINTS_FILE': stable_constraints_file}) }}"
+  when: target_branch in ["stable/ocata", "stable/pike", "stable/queens", "stable/rocky"]
+
+- name: Set OS_TEST_TIMEOUT if requested
+  set_fact:
+    tempest_tox_environment: "{{ tempest_tox_environment | combine({'OS_TEST_TIMEOUT': tempest_test_timeout}) }}"
+  when: tempest_test_timeout != ''
+
 - when:
     - tempest_test_blacklist is defined
   block:
@@ -42,4 +57,4 @@
     chdir: "{{devstack_base_dir}}/tempest"
   become: true
   become_user: tempest
-  environment: '{{ {"OS_TEST_TIMEOUT": tempest_test_timeout} if tempest_test_timeout else {} }}'
+  environment: "{{ tempest_tox_environment }}"