diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index d106f322..f8341094 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
     steps:
     - uses: actions/checkout@v3
     - name: Set up Python ${{ matrix.python-version }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a8d4865..47513665 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@
 - Changed generated client's methods to pass `**kwargs` to base client's `execute` and `execute_ws` methods (breaking change for custom base clients).
 - Added `operation_definition` argument to `generate_client_method` plugin hook.
 - Added `ExtractOperationsPlugin` that extracts operation strings from client methods to separate module.
+- Added Python 3.12 to tested versions.
 
 
 ## 0.9.0 (2023-09-11)
diff --git a/pyproject.toml b/pyproject.toml
index d603006b..2dfb16f0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,6 +18,7 @@ classifiers = [
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
+  "Programming Language :: Python :: 3.12",
   "Topic :: Software Development :: Libraries :: Python Modules",
 ]
 dependencies = [
diff --git a/tests/main/test_main.py b/tests/main/test_main.py
index f26553d2..1a3d2635 100644
--- a/tests/main/test_main.py
+++ b/tests/main/test_main.py
@@ -255,9 +255,11 @@ def test_main_uses_remote_schema_url_and_remote_schema_headers(
     package_path = project_dir / package_name
     assert package_path.is_dir()
     assert_the_same_files_in_directories(package_path, expected_package_path)
-    assert mocked_post.called_with(
-        url="http://test/graphql/", headers={"header1": "value1", "header2": "value2"}
-    )
+    assert "http://test/graphql/" in mocked_post.call_args.args
+    assert mocked_post.call_args.kwargs["headers"] == {
+        "header1": "value1",
+        "header2": "value2",
+    }
 
 
 def test_main_can_read_config_from_provided_file(tmp_path):
diff --git a/tests/test_schema.py b/tests/test_schema.py
index 747ed957..42873867 100644
--- a/tests/test_schema.py
+++ b/tests/test_schema.py
@@ -373,7 +373,7 @@ def test_introspect_remote_schema_uses_provided_headers(mocker):
     introspect_remote_schema("http://testserver/graphql/", headers={"test": "value"})
 
     assert mocked_post.called
-    assert mocked_post.called_with(headers={"test": "value"})
+    assert mocked_post.call_args.kwargs["headers"] == {"test": "value"}
 
 
 @pytest.mark.parametrize("verify_ssl", [True, False])
@@ -388,7 +388,7 @@ def test_introspect_remote_schema_uses_provided_verify_ssl_flag(verify_ssl, mock
     introspect_remote_schema("http://testserver/graphql/", verify_ssl=verify_ssl)
 
     assert mocked_post.called
-    assert mocked_post.called_with(verify=verify_ssl)
+    assert mocked_post.call_args.kwargs["verify"] == verify_ssl
 
 
 def test_get_graphql_queries_returns_schema_definitions_from_single_file(