diff --git a/swh/icinga_plugins/tests/test_vault.py b/swh/icinga_plugins/tests/test_vault.py
--- a/swh/icinga_plugins/tests/test_vault.py
+++ b/swh/icinga_plugins/tests/test_vault.py
@@ -10,33 +10,33 @@
 from .web_scenario import WebScenario
 
 ROOT_URL = "mock://swh-web.example.org"
+DIR_ID = "ab" * 20
 
-dir_id = "ab" * 20
 
 response_pending = {
-    "obj_id": dir_id,
+    "obj_id": DIR_ID,
     "obj_type": "directory",
     "progress_message": "foo",
     "status": "pending",
 }
 
 response_done = {
-    "fetch_url": f"{ROOT_URL}/api/1/vault/directory/{dir_id}/raw/",
+    "fetch_url": f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/raw/",
     "id": 9,
-    "obj_id": dir_id,
+    "obj_id": DIR_ID,
     "obj_type": "directory",
     "status": "done",
 }
 
 response_failed = {
-    "obj_id": dir_id,
+    "obj_id": DIR_ID,
     "obj_type": "directory",
     "progress_message": "foobar",
     "status": "failed",
 }
 
 response_unknown_status = {
-    "obj_id": dir_id,
+    "obj_id": DIR_ID,
     "obj_type": "directory",
     "progress_message": "what",
     "status": "boo",
@@ -48,20 +48,20 @@
         pass
 
     def directory_get_random(self):
-        return bytes.fromhex(dir_id)
+        return bytes.fromhex(DIR_ID)
 
 
 def test_vault_immediate_success(requests_mock, mocker, mocked_time):
     scenario = WebScenario()
 
-    url = f"{ROOT_URL}/api/1/vault/directory/{dir_id}/"
+    url = f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/"
 
     scenario.add_step("get", url, {}, status_code=404)
     scenario.add_step("post", url, response_pending)
     scenario.add_step("get", url, response_done)
     scenario.add_step(
         "get",
-        f"{ROOT_URL}/api/1/vault/directory/{dir_id}/raw/",
+        f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/raw/",
         "this-is-a-tarball",
         headers={"Content-Type": "application/gzip", "Content-Length": "100000"},
     )
@@ -83,7 +83,7 @@
     )
 
     assert result.output == (
-        f"VAULT OK - cooking directory {dir_id} took "
+        f"VAULT OK - cooking directory {DIR_ID} took "
         f"10.00s and succeeded.\n"
         f"| 'total_time' = 10.00s\n"
     )
@@ -93,7 +93,7 @@
 def test_vault_delayed_success(requests_mock, mocker, mocked_time):
     scenario = WebScenario()
 
-    url = f"{ROOT_URL}/api/1/vault/directory/{dir_id}/"
+    url = f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/"
 
     scenario.add_step("get", url, {}, status_code=404)
     scenario.add_step("post", url, response_pending)
@@ -101,7 +101,7 @@
     scenario.add_step("get", url, response_done)
     scenario.add_step(
         "get",
-        f"{ROOT_URL}/api/1/vault/directory/{dir_id}/raw/",
+        f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/raw/",
         "this-is-a-tarball",
         headers={"Content-Type": "application/gzip", "Content-Length": "100000"},
     )
@@ -123,7 +123,7 @@
     )
 
     assert result.output == (
-        f"VAULT OK - cooking directory {dir_id} took "
+        f"VAULT OK - cooking directory {DIR_ID} took "
         f"20.00s and succeeded.\n"
         f"| 'total_time' = 20.00s\n"
     )
@@ -133,7 +133,7 @@
 def test_vault_failure(requests_mock, mocker, mocked_time):
     scenario = WebScenario()
 
-    url = f"{ROOT_URL}/api/1/vault/directory/{dir_id}/"
+    url = f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/"
 
     scenario.add_step("get", url, {}, status_code=404)
     scenario.add_step("post", url, response_pending)
@@ -157,7 +157,7 @@
     )
 
     assert result.output == (
-        f"VAULT CRITICAL - cooking directory {dir_id} took "
+        f"VAULT CRITICAL - cooking directory {DIR_ID} took "
         f"10.00s and failed with: foobar\n"
         f"| 'total_time' = 10.00s\n"
     )
@@ -167,7 +167,7 @@
 def test_vault_unknown_status(requests_mock, mocker, mocked_time):
     scenario = WebScenario()
 
-    url = f"{ROOT_URL}/api/1/vault/directory/{dir_id}/"
+    url = f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/"
 
     scenario.add_step("get", url, {}, status_code=404)
     scenario.add_step("post", url, response_pending)
@@ -191,7 +191,7 @@
     )
 
     assert result.output == (
-        f"VAULT CRITICAL - cooking directory {dir_id} took "
+        f"VAULT CRITICAL - cooking directory {DIR_ID} took "
         f"10.00s and resulted in unknown status: boo\n"
         f"| 'total_time' = 10.00s\n"
     )
@@ -201,7 +201,7 @@
 def test_vault_timeout(requests_mock, mocker, mocked_time):
     scenario = WebScenario()
 
-    url = f"{ROOT_URL}/api/1/vault/directory/{dir_id}/"
+    url = f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/"
 
     scenario.add_step("get", url, {}, status_code=404)
     scenario.add_step("post", url, response_pending)
@@ -226,7 +226,7 @@
     )
 
     assert result.output == (
-        f"VAULT CRITICAL - cooking directory {dir_id} took more than "
+        f"VAULT CRITICAL - cooking directory {DIR_ID} took more than "
         f"4020.00s and has status: foo\n"
         f"| 'total_time' = 4020.00s\n"
     )
@@ -238,7 +238,7 @@
     test that vault_check requests another one."""
     scenario = WebScenario()
 
-    url = f"{ROOT_URL}/api/1/vault/directory/{dir_id}/"
+    url = f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/"
 
     scenario.add_step("get", url, {}, status_code=200)
     scenario.add_step("get", url, {}, status_code=404)
@@ -246,7 +246,7 @@
     scenario.add_step("get", url, response_done)
     scenario.add_step(
         "get",
-        f"{ROOT_URL}/api/1/vault/directory/{dir_id}/raw/",
+        f"{ROOT_URL}/api/1/vault/directory/{DIR_ID}/raw/",
         "this-is-a-tarball",
         headers={"Content-Type": "application/gzip", "Content-Length": "100000"},
     )
@@ -268,7 +268,7 @@
     )
 
     assert result.output == (
-        f"VAULT OK - cooking directory {dir_id} took "
+        f"VAULT OK - cooking directory {DIR_ID} took "
         f"10.00s and succeeded.\n"
         f"| 'total_time' = 10.00s\n"
     )