diff --git a/.circleci/config.yml b/.circleci/config.yml
index 65a3521..8d5f648 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -3,20 +3,18 @@ workflows:
   version: 2
   test:
     jobs:
+      - test-3.13
+      - test-3.12
+      - test-3.11
       - test-3.10
       - test-3.9
-      - test-3.8
-      - test-3.7
-      - test-3.6
-      - test-3.5
-      - test-3.4
       - test-2.7
       - test-pypy3
       - test-pypy2
 jobs:
-  test-3.10: &test-template
+  test-3.13: &test-template
     docker:
-      - image: python:3.10 # We run one test in non-alpine environment, just in case
+      - image: python:3.13 # We run one test in non-alpine environment, just in case
     working_directory: ~/work
     steps:
       - checkout
@@ -37,30 +35,22 @@ jobs:
           command: |
             . venv/bin/activate
             pytest -v
-  test-3.9:
-    <<: *test-template
-    docker:
-      - image: python:3.9-alpine
-  test-3.8:
+  test-3.12:
     <<: *test-template
     docker:
-      - image: python:3.8-alpine
-  test-3.7:
+      - image: python:3.12-alpine
+  test-3.11:
     <<: *test-template
     docker:
-      - image: python:3.7-alpine
-  test-3.6:
+      - image: python:3.11-alpine
+  test-3.10:
     <<: *test-template
     docker:
-      - image: python:3.6-alpine
-  test-3.5:
-    <<: *test-template
-    docker:
-      - image: python:3.5-alpine
-  test-3.4:
+      - image: python:3.10-alpine
+  test-3.9:
     <<: *test-template
     docker:
-      - image: python:3.4-alpine
+      - image: python:3.9-alpine
   test-2.7:
     <<: *test-template
     docker:
diff --git a/setup.py b/setup.py
index 36420e9..a863563 100644
--- a/setup.py
+++ b/setup.py
@@ -12,14 +12,11 @@
 
 setup(
     name='smpplib',
-    version='2.2.3',
+    version='2.2.4',
     url='https://github.com/python-smpplib/python-smpplib',
     description='SMPP library for python',
     packages=find_packages(),
     install_requires=['six'],
-    extras_require=dict(
-        tests=('typing; python_version < "3.5"', 'pytest', 'mock'),
-    ),
     zip_safe=True,
     classifiers=(
         'Development Status :: 5 - Production/Stable',
@@ -29,10 +26,11 @@
         'Programming Language :: Python :: 2',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
+        'Programming Language :: Python :: 3.13',
         'Programming Language :: Python',
         'Topic :: Communications :: Telephony',
         'Topic :: Communications',
diff --git a/smpplib/tests/test_client.py b/smpplib/tests/test_client.py
index a10666f..bc6e196 100644
--- a/smpplib/tests/test_client.py
+++ b/smpplib/tests/test_client.py
@@ -1,6 +1,6 @@
 import warnings
 import pytest
-from mock import Mock, call
+from unittest.mock import Mock, call
 
 from smpplib.client import Client
 from smpplib.smpp import make_pdu
diff --git a/smpplib/tests/test_gsm.py b/smpplib/tests/test_gsm.py
index b6641fd..3c3ebe5 100644
--- a/smpplib/tests/test_gsm.py
+++ b/smpplib/tests/test_gsm.py
@@ -1,7 +1,7 @@
 # -*- coding: utf8 -*-
 
-import mock
 from pytest import mark, raises
+from unittest import mock
 
 from smpplib import consts
 from smpplib.gsm import gsm_encode, make_parts, make_parts_encoded