diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index efea44b4..0de03222 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -43,6 +43,10 @@ jobs:
       run: |
         uv run ruff check jenkinsapi/ --output-format full
 
+    - name: Lint with mypy
+      run: |
+        uv run mypy || true
+
   build:
     runs-on: ubuntu-latest
     strategy:
diff --git a/jenkinsapi/artifact.py b/jenkinsapi/artifact.py
index 72e73818..76a7809a 100644
--- a/jenkinsapi/artifact.py
+++ b/jenkinsapi/artifact.py
@@ -14,13 +14,17 @@
 import os
 import logging
 import hashlib
-from typing import Any, Literal
+from typing import Any, Literal, TYPE_CHECKING
 
 from jenkinsapi.fingerprint import Fingerprint
 from jenkinsapi.custom_exceptions import ArtifactBroken
 
 log = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.build import Build
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Artifact(object):
     """
diff --git a/jenkinsapi/build.py b/jenkinsapi/build.py
index 2bde2d43..9de71a16 100644
--- a/jenkinsapi/build.py
+++ b/jenkinsapi/build.py
@@ -16,7 +16,7 @@
 import datetime
 
 from time import sleep
-from typing import Iterator, List, Dict, Any
+from typing import TYPE_CHECKING, Iterator, List, Dict, Any
 
 import pytz
 from jenkinsapi import config
@@ -35,6 +35,10 @@
 
 log = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+    from jenkinsapi.job import Job
+
 
 class Build(JenkinsBase):
     """
@@ -238,8 +242,8 @@ def get_upstream_job(self) -> Job | None:
         Get the upstream job object if it exist, None otherwise
         :return: Job or None
         """
-        if self.get_upstream_job_name():
-            return self.get_jenkins_obj().get_job(self.get_upstream_job_name())
+        if name := self.get_upstream_job_name():
+            return self.get_jenkins_obj().get_job(name)
         return None
 
     def get_upstream_build_number(self) -> int | None:
@@ -278,8 +282,8 @@ def get_master_job(self) -> Job | None:
         Get the master job object if it exist, None otherwise
         :return: Job or None
         """
-        if self.get_master_job_name():
-            return self.get_jenkins_obj().get_job(self.get_master_job_name())
+        if name := self.get_master_job_name():
+            return self.get_jenkins_obj().get_job(name)
 
         return None
 
diff --git a/jenkinsapi/credential.py b/jenkinsapi/credential.py
index b3ae7330..69efa38c 100644
--- a/jenkinsapi/credential.py
+++ b/jenkinsapi/credential.py
@@ -83,6 +83,9 @@ class UsernamePasswordCredential(Credential):
     dict
     """
 
+    username: str
+    password: str
+
     def __init__(self, cred_dict: dict) -> None:
         jenkins_class: str = (
             "com.cloudbees.plugins.credentials.impl."
@@ -92,12 +95,11 @@ def __init__(self, cred_dict: dict) -> None:
             cred_dict, jenkins_class
         )
         if "typeName" in cred_dict:
-            username: str = cred_dict["displayName"].split("/")[0]
+            self.username = cred_dict["displayName"].split("/")[0]
         else:
-            username: str = cred_dict["userName"]
+            self.username = cred_dict["userName"]
 
-        self.username: str = username
-        self.password: str = cred_dict.get("password", "")
+        self.password = cred_dict.get("password", "")
 
     def get_attributes(self):
         """
@@ -223,26 +225,31 @@ class SSHKeyCredential(Credential):
     dict
     """
 
+    username: str
+    passphrase: str
+    key_type: int
+    key_value: str
+
     def __init__(self, cred_dict: dict) -> None:
         jenkins_class: str = (
             "com.cloudbees.jenkins.plugins.sshcredentials.impl."
             "BasicSSHUserPrivateKey"
         )
         super(SSHKeyCredential, self).__init__(cred_dict, jenkins_class)
+
         if "typeName" in cred_dict:
-            username: str = cred_dict["displayName"].split(" ")[0]
+            self.username = cred_dict["displayName"].split(" ")[0]
         else:
-            username: str = cred_dict["userName"]
+            self.username = cred_dict["userName"]
 
-        self.username: str = username
-        self.passphrase: str = cred_dict.get("passphrase", "")
+        self.passphrase = cred_dict.get("passphrase", "")
 
         if "private_key" not in cred_dict or cred_dict["private_key"] is None:
-            self.key_type: int = -1
-            self.key_value: str = ""
+            self.key_type = -1
+            self.key_value = ""
         elif cred_dict["private_key"].startswith("-"):
-            self.key_type: int = 0
-            self.key_value: str = cred_dict["private_key"]
+            self.key_type = 0
+            self.key_value = cred_dict["private_key"]
         else:
             raise ValueError("Invalid private_key value")
 
diff --git a/jenkinsapi/credentials.py b/jenkinsapi/credentials.py
index e3953efb..8472de4d 100644
--- a/jenkinsapi/credentials.py
+++ b/jenkinsapi/credentials.py
@@ -6,7 +6,7 @@
 
 from __future__ import annotations
 
-from typing import Iterator
+from typing import TYPE_CHECKING, Iterator, Tuple
 
 import logging
 from urllib.parse import urlencode
@@ -20,6 +20,9 @@
 
 log: logging.Logger = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Credentials(JenkinsBase):
     """
@@ -65,7 +68,7 @@ def iterkeys(self):
     def keys(self):
         return list(self.iterkeys())
 
-    def iteritems(self) -> Iterator[str, "Credential"]:
+    def iteritems(self) -> Iterator[Tuple[str, "Credential"]]:
         for cred in self.credentials.values():
             yield cred.description, cred
 
diff --git a/jenkinsapi/executor.py b/jenkinsapi/executor.py
index 4f691356..c2603d7d 100644
--- a/jenkinsapi/executor.py
+++ b/jenkinsapi/executor.py
@@ -3,12 +3,16 @@
 """
 
 from __future__ import annotations
+from typing import TYPE_CHECKING
 
 from jenkinsapi.jenkinsbase import JenkinsBase
 import logging
 
 log = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Executor(JenkinsBase):
     """
diff --git a/jenkinsapi/executors.py b/jenkinsapi/executors.py
index 84f0b6d2..0c36781b 100644
--- a/jenkinsapi/executors.py
+++ b/jenkinsapi/executors.py
@@ -7,13 +7,16 @@
 from __future__ import annotations
 
 import logging
-from typing import Iterator
+from typing import TYPE_CHECKING, Iterator
 
 from jenkinsapi.executor import Executor
 from jenkinsapi.jenkinsbase import JenkinsBase
 
 log: logging.Logger = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Executors(JenkinsBase):
     """
@@ -27,7 +30,7 @@ def __init__(
         self, baseurl: str, nodename: str, jenkins: "Jenkins"
     ) -> None:
         self.nodename: str = nodename
-        self.jenkins: str = jenkins
+        self.jenkins: "Jenkins" = jenkins
         JenkinsBase.__init__(self, baseurl)
         self.count: int = self._data["numExecutors"]
 
diff --git a/jenkinsapi/fingerprint.py b/jenkinsapi/fingerprint.py
index 2d457cec..48eb6275 100644
--- a/jenkinsapi/fingerprint.py
+++ b/jenkinsapi/fingerprint.py
@@ -6,7 +6,7 @@
 
 import re
 import logging
-from typing import Any
+from typing import TYPE_CHECKING, Any
 
 import requests
 
@@ -15,6 +15,9 @@
 
 log: logging.Logger = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Fingerprint(JenkinsBase):
     """
diff --git a/jenkinsapi/jenkinsbase.py b/jenkinsapi/jenkinsbase.py
index 02eec9f4..bab6f722 100644
--- a/jenkinsapi/jenkinsbase.py
+++ b/jenkinsapi/jenkinsbase.py
@@ -20,6 +20,8 @@ class JenkinsBase(object):
     inherited from
     """
 
+    _data: dict
+
     def __repr__(self):
         return """<%s.%s %s>""" % (
             self.__class__.__module__,
diff --git a/jenkinsapi/job.py b/jenkinsapi/job.py
index 00df4714..350fc358 100644
--- a/jenkinsapi/job.py
+++ b/jenkinsapi/job.py
@@ -6,6 +6,7 @@
 
 import json
 import logging
+from typing import TYPE_CHECKING
 import xml.etree.ElementTree as ET
 import urllib.parse as urlparse
 
@@ -34,6 +35,9 @@
 
 log = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Job(JenkinsBase, MutableJenkinsThing):
     """
diff --git a/jenkinsapi/jobs.py b/jenkinsapi/jobs.py
index 5eff7035..b0f87999 100644
--- a/jenkinsapi/jobs.py
+++ b/jenkinsapi/jobs.py
@@ -5,7 +5,7 @@
 
 from __future__ import annotations
 
-from typing import Iterator
+from typing import TYPE_CHECKING, Iterator, Tuple
 import logging
 import time
 
@@ -14,6 +14,10 @@
 
 log = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+    from jenkinsapi.queue import QueueItem
+
 
 class Jobs(object):
     """
@@ -94,7 +98,7 @@ def __getitem__(self, job_name: str) -> "Job":
         else:
             raise UnknownJob(job_name)
 
-    def iteritems(self) -> Iterator[str, "Job"]:
+    def iteritems(self) -> Iterator[Tuple[str, "Job"]]:
         """
         Iterate over the names & objects for all jobs
         """
diff --git a/jenkinsapi/node.py b/jenkinsapi/node.py
index bf258fb2..0ec21177 100644
--- a/jenkinsapi/node.py
+++ b/jenkinsapi/node.py
@@ -7,6 +7,7 @@
 import json
 import logging
 
+from typing import TYPE_CHECKING, Optional, Union
 import xml.etree.ElementTree as ET
 
 import time
@@ -17,6 +18,9 @@
 
 log = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Node(JenkinsBase):
     """
@@ -24,6 +28,8 @@ class Node(JenkinsBase):
     to the master jenkins instance
     """
 
+    _element_tree: Optional[ET.Element]
+
     def __init__(
         self,
         jenkins_obj: "Jenkins",
@@ -117,6 +123,7 @@ def get_node_attributes(self) -> dict:
         :return: Node attributes dict formatted for Jenkins API request
             to create node
         """
+        launcher: dict[str, object]
         na: dict = self.node_attributes
         if not na.get("credential_description", False):
             # If credentials description is not present - we will create
@@ -372,7 +379,7 @@ def load_config(self) -> None:
         self._config = self.get_config()
         self._get_config_element_tree()
 
-    def upload_config(self, config_xml: str) -> None:
+    def upload_config(self, config_xml: Union[str, bytes]) -> None:
         """
         Uploads config_xml to the config.xml for the node.
         """
@@ -489,7 +496,7 @@ def set_config_element(self, el_name: str, value: str) -> None:
         xml_str = ET.tostring(self._et)
         self.upload_config(xml_str)
 
-    def get_monitor(self, monitor_name: str, poll_monitor=True) -> str:
+    def get_monitor(self, monitor_name: str, poll_monitor=True) -> object:
         """
         Polls the node returning one of the monitors in the monitorData
         branch of the returned node api tree.
@@ -507,60 +514,72 @@ def get_monitor(self, monitor_name: str, poll_monitor=True) -> str:
 
         return monitor_data[full_monitor_name]
 
+    def get_monitor_dict(
+        self,
+        monitor_name: str,
+        poll_monitor: bool = True,
+    ) -> dict:
+        value = self.get_monitor(monitor_name, poll_monitor)
+        if not isinstance(value, dict):
+            raise JenkinsAPIException(
+                f"Monitor {monitor_name!r} did not return a dictionary"
+            )
+        return value
+
     def get_available_physical_memory(self) -> int:
         """
         Returns the node's available physical memory in bytes.
         """
-        monitor_data = self.get_monitor("SwapSpaceMonitor")
+        monitor_data = self.get_monitor_dict("SwapSpaceMonitor")
         return monitor_data["availablePhysicalMemory"]
 
     def get_available_swap_space(self) -> int:
         """
         Returns the node's available swap space in bytes.
         """
-        monitor_data = self.get_monitor("SwapSpaceMonitor")
+        monitor_data = self.get_monitor_dict("SwapSpaceMonitor")
         return monitor_data["availableSwapSpace"]
 
     def get_total_physical_memory(self) -> int:
         """
         Returns the node's total physical memory in bytes.
         """
-        monitor_data = self.get_monitor("SwapSpaceMonitor")
+        monitor_data = self.get_monitor_dict("SwapSpaceMonitor")
         return monitor_data["totalPhysicalMemory"]
 
     def get_total_swap_space(self) -> int:
         """
         Returns the node's total swap space in bytes.
         """
-        monitor_data = self.get_monitor("SwapSpaceMonitor")
+        monitor_data = self.get_monitor_dict("SwapSpaceMonitor")
         return monitor_data["totalSwapSpace"]
 
     def get_workspace_path(self) -> str:
         """
         Returns the local path to the node's Jenkins workspace directory.
         """
-        monitor_data = self.get_monitor("DiskSpaceMonitor")
+        monitor_data = self.get_monitor_dict("DiskSpaceMonitor")
         return monitor_data["path"]
 
     def get_workspace_size(self) -> int:
         """
         Returns the size in bytes of the node's Jenkins workspace directory.
         """
-        monitor_data = self.get_monitor("DiskSpaceMonitor")
+        monitor_data = self.get_monitor_dict("DiskSpaceMonitor")
         return monitor_data["size"]
 
     def get_temp_path(self) -> str:
         """
         Returns the local path to the node's temp directory.
         """
-        monitor_data = self.get_monitor("TemporarySpaceMonitor")
+        monitor_data = self.get_monitor_dict("TemporarySpaceMonitor")
         return monitor_data["path"]
 
     def get_temp_size(self) -> int:
         """
         Returns the size in bytes of the node's temp directory.
         """
-        monitor_data = self.get_monitor("TemporarySpaceMonitor")
+        monitor_data = self.get_monitor_dict("TemporarySpaceMonitor")
         return monitor_data["size"]
 
     def get_architecture(self) -> str:
@@ -568,7 +587,12 @@ def get_architecture(self) -> str:
         Returns the system architecture of the node eg. "Linux (amd64)".
         """
         # no need to poll as the architecture will never change
-        return self.get_monitor("ArchitectureMonitor", poll_monitor=False)
+        value = self.get_monitor("ArchitectureMonitor", poll_monitor=False)
+        if not isinstance(value, str):
+            raise JenkinsAPIException(
+                "Monitor ArchitectureMonitor did not return a string"
+            )
+        return value
 
     def block_until_idle(self, timeout: int, poll_time: int = 5) -> None:
         """
@@ -596,7 +620,7 @@ def get_response_time(self) -> int:
         """
         Returns the node's average response time.
         """
-        monitor_data = self.get_monitor("ResponseTimeMonitor")
+        monitor_data = self.get_monitor_dict("ResponseTimeMonitor")
         return monitor_data["average"]
 
     def get_clock_difference(self) -> int:
@@ -605,5 +629,5 @@ def get_clock_difference(self) -> int:
         the master Jenkins clock.
         Used to detect out of sync clocks.
         """
-        monitor_data = self.get_monitor("ClockMonitor")
+        monitor_data = self.get_monitor_dict("ClockMonitor")
         return monitor_data["diff"]
diff --git a/jenkinsapi/nodes.py b/jenkinsapi/nodes.py
index 03edea01..ed037306 100644
--- a/jenkinsapi/nodes.py
+++ b/jenkinsapi/nodes.py
@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-from typing import Iterator
+from typing import TYPE_CHECKING, Iterator
 
 import logging
 
@@ -17,6 +17,9 @@
 
 log: logging.Logger = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Nodes(JenkinsBase):
     """
diff --git a/jenkinsapi/plugins.py b/jenkinsapi/plugins.py
index 8e3dc6ce..d59b8eeb 100644
--- a/jenkinsapi/plugins.py
+++ b/jenkinsapi/plugins.py
@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-from typing import Generator
+from typing import TYPE_CHECKING, Iterable, Tuple
 import logging
 import time
 import re
@@ -20,9 +20,11 @@
 from jenkinsapi.utils.jsonp_to_json import jsonp_to_json
 from jenkinsapi.utils.manifest import Manifest, read_manifest
 
-
 log: logging.Logger = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class Plugins(JenkinsBase):
     """
@@ -53,18 +55,18 @@ def update_center_dict(self):
     def _poll(self, tree=None):
         return self.get_data(self.baseurl, tree=tree)
 
-    def keys(self) -> list[str]:
+    def keys(self) -> Iterable[str]:
         return self.get_plugins_dict().keys()
 
     __iter__ = keys
 
-    def iteritems(self) -> Generator[str, "Plugin"]:
+    def iteritems(self) -> Iterable[Tuple[str, "Plugin"]]:
         return self._get_plugins()
 
     def values(self) -> list["Plugin"]:
         return [a[1] for a in self.iteritems()]
 
-    def _get_plugins(self) -> Generator[str, "Plugin"]:
+    def _get_plugins(self) -> Iterable[Tuple[str, "Plugin"]]:
         if "plugins" in self._data:
             for p_dict in self._data["plugins"]:
                 yield p_dict["shortName"], Plugin(p_dict)
diff --git a/jenkinsapi/queue.py b/jenkinsapi/queue.py
index 3a80ead5..43d0548f 100644
--- a/jenkinsapi/queue.py
+++ b/jenkinsapi/queue.py
@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-from typing import Iterator, Tuple
+from typing import TYPE_CHECKING, Iterator, Tuple
 import logging
 import time
 from requests import HTTPError
@@ -13,6 +13,11 @@
 
 log: logging.Logger = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.build import Build
+    from jenkinsapi.jenkins import Jenkins
+    from jenkinsapi.job import Job
+
 
 class Queue(JenkinsBase):
     """
@@ -36,12 +41,7 @@ def get_jenkins_obj(self) -> "Jenkins":
 
     def iteritems(self) -> Iterator[Tuple[str, "QueueItem"]]:
         for item in self._data["items"]:
-            queue_id = item["id"]
-            item_baseurl = "%s/item/%i" % (self.baseurl, queue_id)
-            yield (
-                item["id"],
-                QueueItem(baseurl=item_baseurl, jenkins_obj=self.jenkins),
-            )
+            yield item["id"], self._get_queue_item(item)
 
     def iterkeys(self) -> Iterator[str]:
         for item in self._data["items"]:
@@ -49,7 +49,7 @@ def iterkeys(self) -> Iterator[str]:
 
     def itervalues(self) -> Iterator["QueueItem"]:
         for item in self._data["items"]:
-            yield QueueItem(self.jenkins, **item)
+            yield self._get_queue_item(item)
 
     def keys(self) -> list[str]:
         return list(self.iterkeys())
@@ -70,14 +70,19 @@ def __getitem__(self, item_id: str) -> "QueueItem":
     def _get_queue_items_for_job(self, job_name: str) -> Iterator["QueueItem"]:
         for item in self._data["items"]:
             if "name" in item["task"] and item["task"]["name"] == job_name:
-                yield QueueItem(
-                    self.get_queue_item_url(item), jenkins_obj=self.jenkins
-                )
+                yield self._get_queue_item(item)
 
     def get_queue_items_for_job(self, job_name: str):
         return list(self._get_queue_items_for_job(job_name))
 
-    def get_queue_item_url(self, item: str) -> str:
+    def _get_queue_item(self, item: dict) -> QueueItem:
+        """Get a QueueItem object from a queue item dict"""
+        return QueueItem(
+            baseurl=self.get_queue_item_url(item),
+            jenkins_obj=self.jenkins,
+        )
+
+    def get_queue_item_url(self, item: dict) -> str:
         return "%s/item/%i" % (self.baseurl, item["id"])
 
     def delete_item(self, queue_item: "QueueItem"):
diff --git a/jenkinsapi/result_set.py b/jenkinsapi/result_set.py
index 5bf5394f..e821fba1 100644
--- a/jenkinsapi/result_set.py
+++ b/jenkinsapi/result_set.py
@@ -3,10 +3,15 @@
 """
 
 from __future__ import annotations
+from typing import TYPE_CHECKING
 
 from jenkinsapi.jenkinsbase import JenkinsBase
 from jenkinsapi.result import Result
 
+if TYPE_CHECKING:
+    from jenkinsapi.build import Build
+    from jenkinsapi.jenkins import Jenkins
+
 
 class ResultSet(JenkinsBase):
     """
diff --git a/jenkinsapi/utils/simple_post_logger.py b/jenkinsapi/utils/simple_post_logger.py
index 29dbce36..4a80c452 100755
--- a/jenkinsapi/utils/simple_post_logger.py
+++ b/jenkinsapi/utils/simple_post_logger.py
@@ -1,14 +1,7 @@
 #!/usr/bin/env python
 
-try:
-    from SimpleHTTPServer import SimpleHTTPRequestHandler
-except ImportError:
-    from http.server import SimpleHTTPRequestHandler
-
-try:
-    import SocketServer as socketserver
-except ImportError:
-    import socketserver
+from http.server import SimpleHTTPRequestHandler
+import socketserver
 
 import logging
 import cgi
diff --git a/jenkinsapi/view.py b/jenkinsapi/view.py
index c9298608..8551a387 100644
--- a/jenkinsapi/view.py
+++ b/jenkinsapi/view.py
@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-from typing import Iterator, Tuple
+from typing import TYPE_CHECKING, Iterable, Iterator, Tuple
 
 import logging
 
@@ -15,6 +15,9 @@
 
 log: logging.Logger = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from jenkinsapi.jenkins import Jenkins
+
 
 class View(JenkinsBase):
     """
@@ -56,7 +59,7 @@ def delete(self) -> None:
         self.jenkins_obj.poll()
         self.deleted = True
 
-    def keys(self) -> list[str]:
+    def keys(self) -> Iterable[str]:
         return self.get_job_dict().keys()
 
     def iteritems(self) -> Iterator[Tuple[str, Job]]:
diff --git a/jenkinsapi_tests/systests/test_nodes.py b/jenkinsapi_tests/systests/test_nodes.py
index 9027d7df..c48ddc94 100644
--- a/jenkinsapi_tests/systests/test_nodes.py
+++ b/jenkinsapi_tests/systests/test_nodes.py
@@ -316,3 +316,8 @@ def test_offline_reason(jenkins):
     assert node.offline_reason() == "test2"
 
     del jenkins.nodes[node_name]
+
+
+def test_get_node_architecture(jenkins):
+    mn = jenkins.get_node("Built-In Node")
+    assert isinstance(mn.get_architecture(), str)
diff --git a/jenkinsapi_tests/systests/test_scm.py b/jenkinsapi_tests/systests/test_scm.py
index 3558b787..7aad8c6b 100644
--- a/jenkinsapi_tests/systests/test_scm.py
+++ b/jenkinsapi_tests/systests/test_scm.py
@@ -1,10 +1,6 @@
 # '''
 # System tests for `jenkinsapi.jenkins` module.
 # '''
-# To run unittests on python 2.6 please use unittest2 library
-# try:
-# import unittest2 as unittest
-# except ImportError:
 # import unittest
 # from jenkinsapi_tests.systests.base import BaseSystemTest
 # from jenkinsapi_tests.test_utils.random_strings import random_string
diff --git a/jenkinsapi_tests/unittests/test_artifact.py b/jenkinsapi_tests/unittests/test_artifact.py
index 73250d8c..0e83ce52 100644
--- a/jenkinsapi_tests/unittests/test_artifact.py
+++ b/jenkinsapi_tests/unittests/test_artifact.py
@@ -1,15 +1,12 @@
 import pytest
-from mock import Mock, patch, call
+from unittest.mock import Mock, patch, call
 from requests.exceptions import HTTPError
 from jenkinsapi.artifact import Artifact
 from jenkinsapi.jenkinsbase import JenkinsBase
 from jenkinsapi.fingerprint import Fingerprint
 from jenkinsapi.custom_exceptions import ArtifactBroken
 
-try:
-    import unittest2 as unittest
-except ImportError:
-    import unittest
+import unittest
 
 
 @pytest.fixture()
diff --git a/jenkinsapi_tests/unittests/test_executors.py b/jenkinsapi_tests/unittests/test_executors.py
index d582a489..b62d5a5d 100644
--- a/jenkinsapi_tests/unittests/test_executors.py
+++ b/jenkinsapi_tests/unittests/test_executors.py
@@ -1,5 +1,5 @@
 import pytest
-import mock
+from unittest import mock
 from jenkinsapi.jenkins import Jenkins
 from jenkinsapi.executors import Executors
 from jenkinsapi.executor import Executor
diff --git a/jenkinsapi_tests/unittests/test_job.py b/jenkinsapi_tests/unittests/test_job.py
index 068103b8..d5a1a678 100644
--- a/jenkinsapi_tests/unittests/test_job.py
+++ b/jenkinsapi_tests/unittests/test_job.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 import pytest
-import mock
+from unittest import mock
 import json
 from . import configs
 from jenkinsapi.job import Job
diff --git a/jenkinsapi_tests/unittests/test_job_folders.py b/jenkinsapi_tests/unittests/test_job_folders.py
index c3ba53c5..b5dae8b2 100644
--- a/jenkinsapi_tests/unittests/test_job_folders.py
+++ b/jenkinsapi_tests/unittests/test_job_folders.py
@@ -1,5 +1,5 @@
 import pytest
-import mock
+from unittest import mock
 from jenkinsapi.jenkins import JenkinsBase
 
 
diff --git a/jenkinsapi_tests/unittests/test_job_get_all_builds.py b/jenkinsapi_tests/unittests/test_job_get_all_builds.py
index 54385b9b..5b0798bb 100644
--- a/jenkinsapi_tests/unittests/test_job_get_all_builds.py
+++ b/jenkinsapi_tests/unittests/test_job_get_all_builds.py
@@ -1,10 +1,6 @@
-import mock
+from unittest import mock
 
-# To run unittests on python 2.6 please use unittest2 library
-try:
-    import unittest2 as unittest
-except ImportError:
-    import unittest
+import unittest
 
 from jenkinsapi import config
 from jenkinsapi.job import Job
diff --git a/jenkinsapi_tests/unittests/test_job_scm_hg.py b/jenkinsapi_tests/unittests/test_job_scm_hg.py
index 925d2bdd..cbb16c58 100644
--- a/jenkinsapi_tests/unittests/test_job_scm_hg.py
+++ b/jenkinsapi_tests/unittests/test_job_scm_hg.py
@@ -1,11 +1,7 @@
 # flake8: noqa
-#    import mock
+#    from unittest import mock
 #
-#    # To run unittests on python 2.6 please use unittest2 library
-#    try:
-#        import unittest2 as unittest
-#    except ImportError:
-#        import unittest
+#    import unittest
 #
 #    from jenkinsapi import config
 #    from jenkinsapi.job import Job
diff --git a/jenkinsapi_tests/unittests/test_plugins.py b/jenkinsapi_tests/unittests/test_plugins.py
index 06da2990..21b13487 100644
--- a/jenkinsapi_tests/unittests/test_plugins.py
+++ b/jenkinsapi_tests/unittests/test_plugins.py
@@ -2,17 +2,11 @@
 jenkinsapi_tests.test_plugins
 """
 
-import mock
-
-# To run unittests on python 2.6 please use unittest2 library
-try:
-    import unittest2 as unittest
-except ImportError:
-    import unittest
-try:
-    from StringIO import StringIO  # python2
-except ImportError:
-    from io import BytesIO as StringIO  # python3
+from unittest import mock
+
+import unittest
+
+from io import BytesIO
 import zipfile
 
 from jenkinsapi.jenkins import Requester
@@ -227,7 +221,7 @@ def test_install_plugin_good_input(
     @mock.patch.object(Plugins, "_poll")
     @mock.patch.object(Plugins, "plugin_version_already_installed")
     @mock.patch.object(
-        Plugins, "restart_required", new_callable=mock.mock.PropertyMock
+        Plugins, "restart_required", new_callable=mock.PropertyMock
     )
     @mock.patch.object(Plugins, "_wait_until_plugin_installed")
     @mock.patch.object(Requester, "post_xml_and_confirm_status")
@@ -253,7 +247,7 @@ def test_install_plugins_good_input_no_restart_required(
     @mock.patch.object(Plugins, "_poll")
     @mock.patch.object(Plugins, "plugin_version_already_installed")
     @mock.patch.object(
-        Plugins, "restart_required", new_callable=mock.mock.PropertyMock
+        Plugins, "restart_required", new_callable=mock.PropertyMock
     )
     @mock.patch.object(Plugins, "_wait_until_plugin_installed")
     @mock.patch.object(Requester, "post_xml_and_confirm_status")
@@ -282,7 +276,7 @@ def test_get_plugin_dependencies(self, _poll_plugins):
             "bla: somestuff\n"
             "Plugin-Dependencies: aws-java-sdk:1.10.45,aws-credentials:1.15"
         )
-        downloaded_plugin = StringIO()
+        downloaded_plugin = BytesIO()
         zipfile.ZipFile(downloaded_plugin, mode="w").writestr(
             "META-INF/MANIFEST.MF", manifest
         )
@@ -317,7 +311,7 @@ def test_plugin_version_already_installed(self, _poll_plugins, _update):
     @mock.patch.object(
         Plugins,
         "update_center_install_status",
-        new_callable=mock.mock.PropertyMock,
+        new_callable=mock.PropertyMock,
     )
     def test_restart_required_after_plugin_installation(
         self, status, _poll_plugins
@@ -344,7 +338,7 @@ def test_restart_required_after_plugin_installation(
     @mock.patch.object(
         Plugins,
         "update_center_install_status",
-        new_callable=mock.mock.PropertyMock,
+        new_callable=mock.PropertyMock,
     )
     def test_restart_not_required_after_plugin_installation(
         self, status, _poll_plugins
diff --git a/jenkinsapi_tests/unittests/test_requester.py b/jenkinsapi_tests/unittests/test_requester.py
index 925696bf..e9ab0289 100644
--- a/jenkinsapi_tests/unittests/test_requester.py
+++ b/jenkinsapi_tests/unittests/test_requester.py
@@ -2,7 +2,7 @@
 import requests
 from jenkinsapi.jenkins import Requester
 from jenkinsapi.custom_exceptions import JenkinsAPIException
-from mock import patch
+from unittest.mock import patch
 
 
 def test_no_parameters_uses_default_values():
diff --git a/jenkinsapi_tests/unittests/test_result_set.py b/jenkinsapi_tests/unittests/test_result_set.py
index 78562b05..8d46b0ca 100644
--- a/jenkinsapi_tests/unittests/test_result_set.py
+++ b/jenkinsapi_tests/unittests/test_result_set.py
@@ -1,10 +1,6 @@
-import mock
+from unittest import mock
 
-# To run unittests on python 2.6 please use unittest2 library
-try:
-    import unittest2 as unittest
-except ImportError:
-    import unittest
+import unittest
 
 from jenkinsapi.result_set import ResultSet
 from jenkinsapi.result import Result
diff --git a/pyproject.toml b/pyproject.toml
index 0bfe2670..509570b7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -64,6 +64,9 @@ upload-dir = "doc/build/html"
 [tool.distutils.bdist_wheel]
 universal = 1
 
+[tool.mypy]
+files = "jenkinsapi, jenkinsapi_tests"
+
 [tool.pycodestyle]
 exclude = ".tox,doc/source/conf.py,build,.venv,.eggs"
 max-line-length = "99"
@@ -77,10 +80,12 @@ dev = [
     "astroid>=1.4.8",
     "pylint>=1.7.1",
     "tox>=2.3.1",
-    "mock>=5.1.0",
     "codecov>=2.1.13",
     "requests-kerberos>=0.15.0",
     "ruff>=0.9.6",
+    "mypy",
+    "types-pytz",
+    "types-requests",
 ]
 docs = [
     "docutils>=0.20.1",