diff --git a/examples/maintenance.py b/examples/maintenance.py
index b2ea37be7..f4b3628b5 100755
--- a/examples/maintenance.py
+++ b/examples/maintenance.py
@@ -38,27 +38,27 @@
 
 for s in j.permissionschemes():
     if " for Project" in s["name"]:
-        logging.info("Deleting permission scheme: %s" % s["name"])
+        logging.info(f"Deleting permission scheme: {s['name']}")
         try:
             j.delete_permissionscheme(s["id"])
         except JIRAError as e:
             logging.error(e.text)
     else:
-        logging.info("Permission scheme: %s" % s["name"])
+        logging.info(f"Permission scheme: {s['name']}")
 
 for s in j.issuesecurityschemes():
     if " for Project" in s["name"]:
         logging.info("Deleting issue security scheme: %s", s["name"])
         j.delete_permissionscheme(s["id"])
     else:
-        logging.error("Issue security scheme: %s" % s["name"])
+        logging.error(f"Issue security scheme: {s['name']}")
 
 for s in j.projectcategories():
     # if ' for Project' in s['name']:
     #     print("Deleting issue security scheme: %s" % s['name'])
     #     # j.delete_permissionscheme(s['id'])
     # else:
-    logging.info("Project category: %s" % s["name"])
+    logging.info(f"Project category: {s['name']}")
 
 for s in j.avatars("project"):
     logging.info("Avatar project: %s", s)
diff --git a/tests/conftest.py b/tests/conftest.py
index e6da6217e..ee3162fb1 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -278,20 +278,11 @@ def create_some_data(self):
         self.jid = get_unique_project_name()
 
         self.project_a = self.jid + "A"  # old XSS
-        self.project_a_name = "Test user={} key={} A".format(
-            getpass.getuser(),
-            self.project_a,
-        )
+        self.project_a_name = f"Test user={getpass.getuser()} key={self.project_a} A"
         self.project_b = self.jid + "B"  # old BULK
-        self.project_b_name = "Test user={} key={} B".format(
-            getpass.getuser(),
-            self.project_b,
-        )
+        self.project_b_name = f"Test user={getpass.getuser()} key={self.project_b} B"
         self.project_sd = self.jid + "C"
-        self.project_sd_name = "Test user={} key={} C".format(
-            getpass.getuser(),
-            self.project_sd,
-        )
+        self.project_sd_name = f"Test user={getpass.getuser()} key={self.project_sd} C"
 
         self.project_a_id = self._create_project(self.project_a, self.project_a_name)
         self.project_b_id = self._create_project(
@@ -306,17 +297,17 @@ def create_some_data(self):
             "issuetype": {"name": self.CI_JIRA_ISSUE},
         }
         self.project_b_issue1_obj = self.jira_admin.create_issue(
-            summary="issue 1 from %s" % self.project_b, **project_b_issue_kwargs
+            summary=f"issue 1 from {self.project_b}", **project_b_issue_kwargs
         )
         self.project_b_issue1 = self.project_b_issue1_obj.key
 
         self.project_b_issue2_obj = self.jira_admin.create_issue(
-            summary="issue 2 from %s" % self.project_b, **project_b_issue_kwargs
+            summary=f"issue 2 from {self.project_b}", **project_b_issue_kwargs
         )
         self.project_b_issue2 = self.project_b_issue2_obj.key
 
         self.project_b_issue3_obj = self.jira_admin.create_issue(
-            summary="issue 3 from %s" % self.project_b, **project_b_issue_kwargs
+            summary=f"issue 3 from {self.project_b}", **project_b_issue_kwargs
         )
         self.project_b_issue3 = self.project_b_issue3_obj.key
 
diff --git a/tests/resources/test_filter.py b/tests/resources/test_filter.py
index 43d2b705e..ac64f3aa9 100644
--- a/tests/resources/test_filter.py
+++ b/tests/resources/test_filter.py
@@ -8,7 +8,7 @@ def setUp(self):
         self.issue_2 = self.test_manager.project_b_issue2
 
     def test_filter(self):
-        jql = "project = %s and component is not empty" % self.project_b
+        jql = f"project = {self.project_b} and component is not empty"
         name = "same filter " + rndstr()
         myfilter = self.jira.create_filter(
             name=name, description="just some new test filter", jql=jql, favourite=False
@@ -19,7 +19,7 @@ def test_filter(self):
 
     def test_favourite_filters(self):
         # filters = self.jira.favourite_filters()
-        jql = "project = %s and component is not empty" % self.project_b
+        jql = f"project = {self.project_b} and component is not empty"
         name = "filter-to-fav-" + rndstr()
         myfilter = self.jira.create_filter(
             name=name, description="just some new test filter", jql=jql, favourite=True
diff --git a/tests/resources/test_issue.py b/tests/resources/test_issue.py
index 8793fe8c6..1b2326cd1 100644
--- a/tests/resources/test_issue.py
+++ b/tests/resources/test_issue.py
@@ -16,7 +16,7 @@ def setUp(self):
     def test_issue(self):
         issue = self.jira.issue(self.issue_1)
         self.assertEqual(issue.key, self.issue_1)
-        self.assertEqual(issue.fields.summary, "issue 1 from %s" % self.project_b)
+        self.assertEqual(issue.fields.summary, f"issue 1 from {self.project_b}")
 
     def test_issue_search_finds_issue(self):
         issues = self.jira.search_issues("key=%s" % self.issue_1)
@@ -62,7 +62,7 @@ def test_issue_get_field(self):
 
     def test_issue_field_limiting(self):
         issue = self.jira.issue(self.issue_2, fields="summary,comment")
-        self.assertEqual(issue.fields.summary, "issue 2 from %s" % self.project_b)
+        self.assertEqual(issue.fields.summary, f"issue 2 from {self.project_b}")
         comment1 = self.jira.add_comment(issue, "First comment")
         comment2 = self.jira.add_comment(issue, "Second comment")
         comment3 = self.jira.add_comment(issue, "Third comment")
@@ -77,7 +77,7 @@ def test_issue_field_limiting(self):
     def test_issue_equal(self):
         issue1 = self.jira.issue(self.issue_1)
         issue2 = self.jira.issue(self.issue_2)
-        issues = self.jira.search_issues("key=%s" % self.issue_1)
+        issues = self.jira.search_issues(f"key={self.issue_1}")
         self.assertTrue(issue1 is not None)
         self.assertTrue(issue1 == issues[0])
         self.assertFalse(issue2 == issues[0])
diff --git a/tests/resources/test_project.py b/tests/resources/test_project.py
index 4c8096525..1617ae5f7 100644
--- a/tests/resources/test_project.py
+++ b/tests/resources/test_project.py
@@ -107,7 +107,7 @@ def test_project_components(self):
         component.delete()
 
     def test_project_versions(self):
-        name = "version-%s" % rndstr()
+        name = f"version-{rndstr()}"
         version = self.jira.create_version(name, self.project_b, "will be deleted soon")
         versions = self.jira.project_versions(self.project_b)
         self.assertGreaterEqual(len(versions), 1)
@@ -121,9 +121,9 @@ def test_project_versions(self):
 
     def test_update_project_version(self):
         # given
-        name = "version-%s" % rndstr()
+        name = f"version-{rndstr()}"
         version = self.jira.create_version(name, self.project_b, "will be deleted soon")
-        updated_name = "version-%s" % rndstr()
+        updated_name = f"version-{rndstr()}"
         # when
         version.update(name=updated_name)
         # then
@@ -131,7 +131,7 @@ def test_update_project_version(self):
         version.delete()
 
     def test_get_project_version_by_name(self):
-        name = "version-%s" % rndstr()
+        name = f"version-{rndstr()}"
         version = self.jira.create_version(name, self.project_b, "will be deleted soon")
 
         found_version = self.jira.get_project_version_by_name(self.project_b, name)
@@ -148,7 +148,7 @@ def test_get_project_version_by_name(self):
         version.delete()
 
     def test_rename_version(self):
-        old_name = "version-%s" % rndstr()
+        old_name = f"version-{rndstr()}"
         version = self.jira.create_version(
             old_name, self.project_b, "will be deleted soon"
         )
@@ -170,7 +170,7 @@ def test_rename_version(self):
         version.delete()
 
     def test_project_versions_with_project_obj(self):
-        name = "version-%s" % rndstr()
+        name = f"version-{rndstr()}"
         version = self.jira.create_version(name, self.project_b, "will be deleted soon")
         project = self.jira.project(self.project_b)
         versions = self.jira.project_versions(project)
diff --git a/tests/resources/test_status.py b/tests/resources/test_status.py
index e497ace96..7bb33c079 100644
--- a/tests/resources/test_status.py
+++ b/tests/resources/test_status.py
@@ -12,5 +12,5 @@ def test_statuses(self):
                 s = self.jira.status(status.id)
                 self.assertEqual(s.id, status.id)
                 break
-        self.assertTrue(found, "Status Done not found. [%s]" % statuses)
+        self.assertTrue(found, f"Status Done not found. [{statuses}]")
         self.assertGreater(len(statuses), 0)
diff --git a/tests/resources/test_status_category.py b/tests/resources/test_status_category.py
index 3eaadc615..117d0a15d 100644
--- a/tests/resources/test_status_category.py
+++ b/tests/resources/test_status_category.py
@@ -10,7 +10,7 @@ def test_statuscategories(self):
                 found = True
                 break
         self.assertTrue(
-            found, "StatusCategory with id=1 not found. [%s]" % statuscategories
+            found, f"StatusCategory with id=1 not found. [{statuscategories}]"
         )
         self.assertGreater(len(statuscategories), 0)
 
diff --git a/tests/test_client.py b/tests/test_client.py
index 0fedd8f8f..6aec7ada4 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -64,9 +64,7 @@ def test_delete_inexistent_project(cl_admin):
 
     assert "No project could be found with key" in str(
         ex.value
-    ) or 'Parameter pid="%s" is not a Project, projectID or slug' % slug in str(
-        ex.value
-    )
+    ) or f'Parameter pid="{slug}" is not a Project, projectID or slug' in str(ex.value)
 
 
 def test_templates(cl_admin):
diff --git a/tests/tests.py b/tests/tests.py
index ee0b109f8..c2a673cad 100755
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -184,7 +184,7 @@ def setUp(self):
         self.issue = self.test_manager.project_b_issue1
 
     def test_search_issues(self):
-        issues = self.jira.search_issues("project=%s" % self.project_b)
+        issues = self.jira.search_issues(f"project={self.project_b}")
         issues = cast(ResultList[Issue], issues)
         self.assertLessEqual(len(issues), 50)  # default maxResults
         for issue in issues:
@@ -195,7 +195,7 @@ def test_search_issues_async(self):
         try:
             self.jira._options["async"] = True
             issues = self.jira.search_issues(
-                "project=%s" % self.project_b, maxResults=False
+                f"project={self.project_b}", maxResults=False
             )
             issues = cast(ResultList[Issue], issues)
             self.assertEqual(len(issues), issues.total)
@@ -205,20 +205,18 @@ def test_search_issues_async(self):
             self.jira._options["async"] = original_val
 
     def test_search_issues_maxresults(self):
-        issues = self.jira.search_issues("project=%s" % self.project_b, maxResults=10)
+        issues = self.jira.search_issues(f"project={self.project_b}", maxResults=10)
         self.assertLessEqual(len(issues), 10)
 
     def test_search_issues_startat(self):
         issues = self.jira.search_issues(
-            "project=%s" % self.project_b, startAt=2, maxResults=10
+            f"project={self.project_b}", startAt=2, maxResults=10
         )
         self.assertGreaterEqual(len(issues), 1)
         # we know that project_b should have at least 3 issues
 
     def test_search_issues_field_limiting(self):
-        issues = self.jira.search_issues(
-            "key=%s" % self.issue, fields="summary,comment"
-        )
+        issues = self.jira.search_issues(f"key={self.issue}", fields="summary,comment")
         issues = cast(ResultList[Issue], issues)
         self.assertTrue(hasattr(issues[0].fields, "summary"))
         self.assertTrue(hasattr(issues[0].fields, "comment"))
@@ -226,7 +224,7 @@ def test_search_issues_field_limiting(self):
         self.assertFalse(hasattr(issues[0].fields, "progress"))
 
     def test_search_issues_expand(self):
-        issues = self.jira.search_issues("key=%s" % self.issue, expand="changelog")
+        issues = self.jira.search_issues(f"key={self.issue}", expand="changelog")
         issues = cast(ResultList[Issue], issues)
         # self.assertTrue(hasattr(issues[0], 'names'))
         self.assertEqual(len(issues), 1)
@@ -331,7 +329,7 @@ def test_fetch_pages(
         batch_size = batch_size or MIMICKED_BACKEND_BATCH_SIZE
         expected_results = []
         for i in range(0, total):
-            result = _create_issue_result_json(i, "summary %s" % i, key="KEY-%s" % i)
+            result = _create_issue_result_json(i, f"summary {i}", key=f"KEY-{i}")
             expected_results.append(result)
 
         if not max_results:
@@ -406,10 +404,10 @@ def test_get_batch_size(default_batch_sizes, item_type, expected, no_fields):
 def _create_issue_result_json(issue_id, summary, key, **kwargs):
     """Returns a minimal json object for an issue."""
     return {
-        "id": "%s" % issue_id,
+        "id": f"{issue_id}",
         "summary": summary,
         "key": key,
-        "self": kwargs.get("self", "http://example.com/%s" % issue_id),
+        "self": kwargs.get("self", f"http://example.com/{issue_id}"),
     }
 
 
@@ -499,10 +497,10 @@ def test_kill_websudo(self):
 class UserAdministrationTests(JiraTestCase):
     def setUp(self):
         JiraTestCase.setUp(self)
-        self.test_username = "test_%s" % self.test_manager.project_a
-        self.test_email = "%s@example.com" % self.test_username
+        self.test_username = f"test_{self.test_manager.project_a}"
+        self.test_email = f"{self.test_username}@example.com"
         self.test_password = rndpassword()
-        self.test_groupname = "testGroupFor_%s" % self.test_manager.project_a
+        self.test_groupname = f"testGroupFor_{self.test_manager.project_a}"
 
     def _skip_pycontribs_instance(self):
         pytest.skip(