diff --git a/gitlab/base.py b/gitlab/base.py
index e813fcd92..6fe1ab1fe 100644
--- a/gitlab/base.py
+++ b/gitlab/base.py
@@ -21,7 +21,7 @@
 import pprint
 import textwrap
 from types import ModuleType
-from typing import Any, Dict, Iterable, Optional, Type, Union
+from typing import Any, Dict, Iterable, Optional, Type, TYPE_CHECKING, Union
 
 import gitlab
 from gitlab import types as g_types
@@ -245,14 +245,22 @@ def get_id(self) -> Optional[Union[int, str]]:
         """Returns the id of the resource."""
         if self._id_attr is None or not hasattr(self, self._id_attr):
             return None
-        return getattr(self, self._id_attr)
+        id_val = getattr(self, self._id_attr)
+        if id_val is None:
+            return None
+        if TYPE_CHECKING:
+            assert isinstance(id_val, (int, str))
+        return id_val
 
     @property
     def _repr_value(self) -> Optional[str]:
         """Safely returns the human-readable resource name if present."""
         if self._repr_attr is None or not hasattr(self, self._repr_attr):
             return None
-        return getattr(self, self._repr_attr)
+        repr_val = getattr(self, self._repr_attr)
+        if TYPE_CHECKING:
+            assert isinstance(repr_val, str)
+        return repr_val
 
     @property
     def encoded_id(self) -> Optional[Union[int, str]]:
diff --git a/gitlab/cli.py b/gitlab/cli.py
index 979396407..e5c85e3b1 100644
--- a/gitlab/cli.py
+++ b/gitlab/cli.py
@@ -23,7 +23,18 @@
 import re
 import sys
 from types import ModuleType
-from typing import Any, Callable, cast, Dict, Optional, Tuple, Type, TypeVar, Union
+from typing import (
+    Any,
+    Callable,
+    cast,
+    Dict,
+    Optional,
+    Tuple,
+    Type,
+    TYPE_CHECKING,
+    TypeVar,
+    Union,
+)
 
 from requests.structures import CaseInsensitiveDict
 
@@ -96,8 +107,11 @@ def gitlab_resource_to_cls(
 ) -> Type[RESTObject]:
     classes = CaseInsensitiveDict(namespace.__dict__)
     lowercase_class = gitlab_resource.replace("-", "")
-
-    return classes[lowercase_class]
+    class_type = classes[lowercase_class]
+    if TYPE_CHECKING:
+        assert isinstance(class_type, type)
+        assert issubclass(class_type, RESTObject)
+    return class_type
 
 
 def cls_to_gitlab_resource(cls: RESTObject) -> str:
diff --git a/gitlab/client.py b/gitlab/client.py
index e7c44ae5e..e004e7ce6 100644
--- a/gitlab/client.py
+++ b/gitlab/client.py
@@ -44,6 +44,8 @@
     f"api-usage.html#pagination"
 )
 
+HttpResponseType = Union[Dict[str, Any], List[Any], requests.Response]
+
 
 class Gitlab:
     """Represents a GitLab server connection.
@@ -411,7 +413,7 @@ def lint(self, content: str, **kwargs: Any) -> Tuple[bool, List[str]]:
         post_data = {"content": content}
         data = self.http_post("/ci/lint", post_data=post_data, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(data, requests.Response)
+            assert isinstance(data, dict)
         return (data["status"] == "valid", data["errors"])
 
     @gitlab.exceptions.on_http_error(gitlab.exceptions.GitlabMarkdownError)
@@ -438,7 +440,8 @@ def markdown(
             post_data["project"] = project
         data = self.http_post("/markdown", post_data=post_data, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(data, requests.Response)
+            assert isinstance(data, dict)
+            assert isinstance(data["html"], str)
         return data["html"]
 
     @gitlab.exceptions.on_http_error(gitlab.exceptions.GitlabLicenseError)
@@ -478,7 +481,7 @@ def set_license(self, license: str, **kwargs: Any) -> Dict[str, Any]:
         data = {"license": license}
         result = self.http_post("/license", post_data=data, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
     def _set_auth_info(self) -> None:
@@ -777,7 +780,7 @@ def http_get(
         streamed: bool = False,
         raw: bool = False,
         **kwargs: Any,
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> HttpResponseType:
         """Make a GET request to the Gitlab server.
 
         Args:
@@ -808,7 +811,10 @@ def http_get(
             and not raw
         ):
             try:
-                return result.json()
+                json_result = result.json()
+                if TYPE_CHECKING:
+                    assert isinstance(json_result, dict)
+                return json_result
             except Exception as e:
                 raise gitlab.exceptions.GitlabParsingError(
                     error_message="Failed to parse the server message"
@@ -954,7 +960,7 @@ def http_post(
         raw: bool = False,
         files: Optional[Dict[str, Any]] = None,
         **kwargs: Any,
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> HttpResponseType:
         """Make a POST request to the Gitlab server.
 
         Args:
@@ -989,7 +995,10 @@ def http_post(
         )
         try:
             if result.headers.get("Content-Type", None) == "application/json":
-                return result.json()
+                json_result = result.json()
+                if TYPE_CHECKING:
+                    assert isinstance(json_result, dict)
+                return json_result
         except Exception as e:
             raise gitlab.exceptions.GitlabParsingError(
                 error_message="Failed to parse the server message"
@@ -1037,7 +1046,10 @@ def http_put(
             **kwargs,
         )
         try:
-            return result.json()
+            json_result = result.json()
+            if TYPE_CHECKING:
+                assert isinstance(json_result, dict)
+            return json_result
         except Exception as e:
             raise gitlab.exceptions.GitlabParsingError(
                 error_message="Failed to parse the server message"
diff --git a/gitlab/mixins.py b/gitlab/mixins.py
index f33a1fcf7..b323851d6 100644
--- a/gitlab/mixins.py
+++ b/gitlab/mixins.py
@@ -32,6 +32,7 @@
 import requests
 
 import gitlab
+import gitlab.client as gl_client
 from gitlab import base, cli
 from gitlab import exceptions as exc
 from gitlab import utils
@@ -138,7 +139,7 @@ def get(
             return self._obj_cls(self, {self._obj_cls._id_attr: id}, lazy=lazy)
         server_data = self.gitlab.http_get(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(server_data, requests.Response)
+            assert isinstance(server_data, dict)
         return self._obj_cls(self, server_data, lazy=lazy)
 
 
@@ -170,7 +171,7 @@ def get(self, **kwargs: Any) -> base.RESTObject:
             assert self.path is not None
         server_data = self.gitlab.http_get(self.path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(server_data, requests.Response)
+            assert isinstance(server_data, dict)
             assert self._obj_cls is not None
         return self._obj_cls(self, server_data)
 
@@ -204,7 +205,7 @@ def refresh(self, **kwargs: Any) -> None:
             path = self.manager.path
         server_data = self.manager.gitlab.http_get(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(server_data, requests.Response)
+            assert isinstance(server_data, dict)
         self._update_attrs(server_data)
 
 
@@ -309,7 +310,7 @@ def create(
         path = kwargs.pop("path", self.path)
         server_data = self.gitlab.http_post(path, post_data=data, files=files, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(server_data, requests.Response)
+            assert isinstance(server_data, dict)
             assert self._obj_cls is not None
         return self._obj_cls(self, server_data)
 
@@ -326,7 +327,7 @@ class UpdateMixin(_RestManagerBase):
 
     def _get_update_method(
         self,
-    ) -> Callable[..., Union[Dict[str, Any], requests.Response]]:
+    ) -> Callable[..., gl_client.HttpResponseType]:
         """Return the HTTP method to use.
 
         Returns:
@@ -375,7 +376,7 @@ def update(
         http_method = self._get_update_method()
         result = http_method(path, post_data=new_data, files=files, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
 
@@ -562,7 +563,7 @@ def user_agent_detail(self, **kwargs: Any) -> Dict[str, Any]:
         path = f"{self.manager.path}/{self.encoded_id}/user_agent_detail"
         result = self.manager.gitlab.http_get(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
 
@@ -675,7 +676,7 @@ def subscribe(self, **kwargs: Any) -> None:
         path = f"{self.manager.path}/{self.encoded_id}/subscribe"
         server_data = self.manager.gitlab.http_post(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(server_data, requests.Response)
+            assert isinstance(server_data, dict)
         self._update_attrs(server_data)
 
     @cli.register_custom_action(
@@ -695,7 +696,7 @@ def unsubscribe(self, **kwargs: Any) -> None:
         path = f"{self.manager.path}/{self.encoded_id}/unsubscribe"
         server_data = self.manager.gitlab.http_post(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(server_data, requests.Response)
+            assert isinstance(server_data, dict)
         self._update_attrs(server_data)
 
 
@@ -746,12 +747,15 @@ def time_stats(self, **kwargs: Any) -> Dict[str, Any]:
         # Use the existing time_stats attribute if it exist, otherwise make an
         # API call
         if "time_stats" in self.attributes:
-            return self.attributes["time_stats"]
+            time_stats = self.attributes["time_stats"]
+            if TYPE_CHECKING:
+                assert isinstance(time_stats, dict)
+            return time_stats
 
         path = f"{self.manager.path}/{self.encoded_id}/time_stats"
         result = self.manager.gitlab.http_get(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
     @cli.register_custom_action(("ProjectIssue", "ProjectMergeRequest"), ("duration",))
@@ -771,7 +775,7 @@ def time_estimate(self, duration: str, **kwargs: Any) -> Dict[str, Any]:
         data = {"duration": duration}
         result = self.manager.gitlab.http_post(path, post_data=data, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
     @cli.register_custom_action(("ProjectIssue", "ProjectMergeRequest"))
@@ -789,7 +793,7 @@ def reset_time_estimate(self, **kwargs: Any) -> Dict[str, Any]:
         path = f"{self.manager.path}/{self.encoded_id}/reset_time_estimate"
         result = self.manager.gitlab.http_post(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
     @cli.register_custom_action(("ProjectIssue", "ProjectMergeRequest"), ("duration",))
@@ -809,7 +813,7 @@ def add_spent_time(self, duration: str, **kwargs: Any) -> Dict[str, Any]:
         data = {"duration": duration}
         result = self.manager.gitlab.http_post(path, post_data=data, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
     @cli.register_custom_action(("ProjectIssue", "ProjectMergeRequest"))
@@ -827,7 +831,7 @@ def reset_spent_time(self, **kwargs: Any) -> Dict[str, Any]:
         path = f"{self.manager.path}/{self.encoded_id}/reset_spent_time"
         result = self.manager.gitlab.http_post(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
 
@@ -841,7 +845,7 @@ class ParticipantsMixin(_RestObjectBase):
 
     @cli.register_custom_action(("ProjectMergeRequest", "ProjectIssue"))
     @exc.on_http_error(exc.GitlabListError)
-    def participants(self, **kwargs: Any) -> Dict[str, Any]:
+    def participants(self, **kwargs: Any) -> List[Any]:
         """List the participants.
 
         Args:
@@ -861,7 +865,7 @@ def participants(self, **kwargs: Any) -> Dict[str, Any]:
         path = f"{self.manager.path}/{self.encoded_id}/participants"
         result = self.manager.gitlab.http_get(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, list)
         return result
 
 
@@ -889,7 +893,7 @@ def render(self, link_url: str, image_url: str, **kwargs: Any) -> Dict[str, Any]
         data = {"link_url": link_url, "image_url": image_url}
         result = self.gitlab.http_get(path, data, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
 
 
@@ -904,7 +908,7 @@ class PromoteMixin(_RestObjectBase):
 
     def _get_update_method(
         self,
-    ) -> Callable[..., Union[Dict[str, Any], requests.Response]]:
+    ) -> Callable[..., gl_client.HttpResponseType]:
         """Return the HTTP method to use.
 
         Returns:
@@ -936,5 +940,5 @@ def promote(self, **kwargs: Any) -> Dict[str, Any]:
         http_method = self._get_update_method()
         result = http_method(path, **kwargs)
         if TYPE_CHECKING:
-            assert not isinstance(result, requests.Response)
+            assert isinstance(result, dict)
         return result
diff --git a/gitlab/v4/objects/commits.py b/gitlab/v4/objects/commits.py
index 8558ef9ea..0c0372099 100644
--- a/gitlab/v4/objects/commits.py
+++ b/gitlab/v4/objects/commits.py
@@ -1,7 +1,5 @@
 from typing import Any, cast, Dict, List, Optional, TYPE_CHECKING, Union
 
-import requests
-
 import gitlab
 from gitlab import cli
 from gitlab import exceptions as exc
@@ -107,9 +105,7 @@ def merge_requests(
 
     @cli.register_custom_action("ProjectCommit", ("branch",))
     @exc.on_http_error(exc.GitlabRevertError)
-    def revert(
-        self, branch: str, **kwargs: Any
-    ) -> Union[Dict[str, Any], requests.Response]:
+    def revert(self, branch: str, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Revert a commit on a given branch.
 
         Args:
@@ -129,7 +125,7 @@ def revert(
 
     @cli.register_custom_action("ProjectCommit")
     @exc.on_http_error(exc.GitlabGetError)
-    def signature(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def signature(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Get the signature of the commit.
 
         Args:
diff --git a/gitlab/v4/objects/deploy_keys.py b/gitlab/v4/objects/deploy_keys.py
index 0962b4a39..88c9122a7 100644
--- a/gitlab/v4/objects/deploy_keys.py
+++ b/gitlab/v4/objects/deploy_keys.py
@@ -1,7 +1,6 @@
-from typing import Any, cast, Dict, Union
-
-import requests
+from typing import Any, cast, Union
 
+import gitlab
 from gitlab import cli
 from gitlab import exceptions as exc
 from gitlab.base import RESTManager, RESTObject
@@ -38,9 +37,7 @@ class ProjectKeyManager(CRUDMixin, RESTManager):
 
     @cli.register_custom_action("ProjectKeyManager", ("key_id",))
     @exc.on_http_error(exc.GitlabProjectDeployKeyError)
-    def enable(
-        self, key_id: int, **kwargs: Any
-    ) -> Union[Dict[str, Any], requests.Response]:
+    def enable(self, key_id: int, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Enable a deploy key for a project.
 
         Args:
diff --git a/gitlab/v4/objects/environments.py b/gitlab/v4/objects/environments.py
index a8bd9d5dd..6cf0a6ee7 100644
--- a/gitlab/v4/objects/environments.py
+++ b/gitlab/v4/objects/environments.py
@@ -1,7 +1,6 @@
-from typing import Any, cast, Dict, Union
-
-import requests
+from typing import Any, cast, Union
 
+import gitlab
 from gitlab import cli
 from gitlab import exceptions as exc
 from gitlab.base import RESTManager, RESTObject
@@ -26,7 +25,7 @@
 class ProjectEnvironment(SaveMixin, ObjectDeleteMixin, RESTObject):
     @cli.register_custom_action("ProjectEnvironment")
     @exc.on_http_error(exc.GitlabStopError)
-    def stop(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def stop(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Stop the environment.
 
         Args:
diff --git a/gitlab/v4/objects/groups.py b/gitlab/v4/objects/groups.py
index ae7184634..15b79dcd2 100644
--- a/gitlab/v4/objects/groups.py
+++ b/gitlab/v4/objects/groups.py
@@ -1,7 +1,5 @@
 from typing import Any, BinaryIO, cast, Dict, List, Optional, Type, TYPE_CHECKING, Union
 
-import requests
-
 import gitlab
 from gitlab import cli
 from gitlab import exceptions as exc
@@ -332,7 +330,7 @@ def import_group(
         name: str,
         parent_id: Optional[str] = None,
         **kwargs: Any,
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> gitlab.client.HttpResponseType:
         """Import a group from an archive file.
 
         Args:
diff --git a/gitlab/v4/objects/merge_requests.py b/gitlab/v4/objects/merge_requests.py
index 9eb965b93..6bcaf467d 100644
--- a/gitlab/v4/objects/merge_requests.py
+++ b/gitlab/v4/objects/merge_requests.py
@@ -5,8 +5,6 @@
 """
 from typing import Any, cast, Dict, Optional, TYPE_CHECKING, Union
 
-import requests
-
 import gitlab
 from gitlab import cli
 from gitlab import exceptions as exc
@@ -244,7 +242,7 @@ def commits(self, **kwargs: Any) -> RESTObjectList:
 
     @cli.register_custom_action("ProjectMergeRequest")
     @exc.on_http_error(exc.GitlabListError)
-    def changes(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def changes(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """List the merge request changes.
 
         Args:
@@ -313,7 +311,7 @@ def unapprove(self, **kwargs: Any) -> None:
 
     @cli.register_custom_action("ProjectMergeRequest")
     @exc.on_http_error(exc.GitlabMRRebaseError)
-    def rebase(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def rebase(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Attempt to rebase the source branch onto the target branch
 
         Args:
@@ -329,7 +327,7 @@ def rebase(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
 
     @cli.register_custom_action("ProjectMergeRequest")
     @exc.on_http_error(exc.GitlabGetError)
-    def merge_ref(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def merge_ref(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Attempt to merge changes between source and target branches into
             `refs/merge-requests/:iid/merge`.
 
diff --git a/gitlab/v4/objects/pipelines.py b/gitlab/v4/objects/pipelines.py
index eec46a1b9..2bb0d6270 100644
--- a/gitlab/v4/objects/pipelines.py
+++ b/gitlab/v4/objects/pipelines.py
@@ -1,7 +1,6 @@
 from typing import Any, cast, Dict, Optional, TYPE_CHECKING, Union
 
-import requests
-
+import gitlab
 from gitlab import cli
 from gitlab import exceptions as exc
 from gitlab.base import RESTManager, RESTObject
@@ -60,7 +59,7 @@ class ProjectPipeline(RefreshMixin, ObjectDeleteMixin, RESTObject):
 
     @cli.register_custom_action("ProjectPipeline")
     @exc.on_http_error(exc.GitlabPipelineCancelError)
-    def cancel(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def cancel(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Cancel the job.
 
         Args:
@@ -75,7 +74,7 @@ def cancel(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
 
     @cli.register_custom_action("ProjectPipeline")
     @exc.on_http_error(exc.GitlabPipelineRetryError)
-    def retry(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def retry(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Retry the job.
 
         Args:
diff --git a/gitlab/v4/objects/projects.py b/gitlab/v4/objects/projects.py
index 96d802bb0..c1ed23a77 100644
--- a/gitlab/v4/objects/projects.py
+++ b/gitlab/v4/objects/projects.py
@@ -245,7 +245,7 @@ def delete_fork_relation(self, **kwargs: Any) -> None:
 
     @cli.register_custom_action("Project")
     @exc.on_http_error(exc.GitlabGetError)
-    def languages(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def languages(self, **kwargs: Any) -> client.HttpResponseType:
         """Get languages used in the project with percentage value.
 
         Args:
@@ -792,7 +792,7 @@ def import_project(
         overwrite: bool = False,
         override_params: Optional[Dict[str, Any]] = None,
         **kwargs: Any,
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> client.HttpResponseType:
         """Import a project from an archive file.
 
         Args:
@@ -835,7 +835,7 @@ def import_bitbucket_server(
         new_name: Optional[str] = None,
         target_namespace: Optional[str] = None,
         **kwargs: Any,
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> client.HttpResponseType:
         """Import a project from BitBucket Server to Gitlab (schedule the import)
 
         This method will return when an import operation has been safely queued,
@@ -924,7 +924,7 @@ def import_github(
         target_namespace: str,
         new_name: Optional[str] = None,
         **kwargs: Any,
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> client.HttpResponseType:
         """Import a project from Github to Gitlab (schedule the import)
 
         This method will return when an import operation has been safely queued,
diff --git a/gitlab/v4/objects/repositories.py b/gitlab/v4/objects/repositories.py
index e968a6a6a..ca7f409e6 100644
--- a/gitlab/v4/objects/repositories.py
+++ b/gitlab/v4/objects/repositories.py
@@ -24,7 +24,7 @@ class RepositoryMixin(_RestObjectBase):
     @exc.on_http_error(exc.GitlabUpdateError)
     def update_submodule(
         self, submodule: str, branch: str, commit_sha: str, **kwargs: Any
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> gitlab.client.HttpResponseType:
         """Update a project submodule
 
         Args:
@@ -83,7 +83,7 @@ def repository_tree(
     @exc.on_http_error(exc.GitlabGetError)
     def repository_blob(
         self, sha: str, **kwargs: Any
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> gitlab.client.HttpResponseType:
         """Return a file by blob SHA.
 
         Args:
@@ -148,7 +148,7 @@ def repository_raw_blob(
     @exc.on_http_error(exc.GitlabGetError)
     def repository_compare(
         self, from_: str, to: str, **kwargs: Any
-    ) -> Union[Dict[str, Any], requests.Response]:
+    ) -> gitlab.client.HttpResponseType:
         """Return a diff between two branches/commits.
 
         Args:
diff --git a/gitlab/v4/objects/sidekiq.py b/gitlab/v4/objects/sidekiq.py
index c0bf9d249..78420fc57 100644
--- a/gitlab/v4/objects/sidekiq.py
+++ b/gitlab/v4/objects/sidekiq.py
@@ -1,7 +1,6 @@
-from typing import Any, Dict, Union
-
-import requests
+from typing import Any
 
+import gitlab
 from gitlab import cli
 from gitlab import exceptions as exc
 from gitlab.base import RESTManager
@@ -20,7 +19,7 @@ class SidekiqManager(RESTManager):
 
     @cli.register_custom_action("SidekiqManager")
     @exc.on_http_error(exc.GitlabGetError)
-    def queue_metrics(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def queue_metrics(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Return the registered queues information.
 
         Args:
@@ -37,9 +36,7 @@ def queue_metrics(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Respons
 
     @cli.register_custom_action("SidekiqManager")
     @exc.on_http_error(exc.GitlabGetError)
-    def process_metrics(
-        self, **kwargs: Any
-    ) -> Union[Dict[str, Any], requests.Response]:
+    def process_metrics(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Return the registered sidekiq workers.
 
         Args:
@@ -56,7 +53,7 @@ def process_metrics(
 
     @cli.register_custom_action("SidekiqManager")
     @exc.on_http_error(exc.GitlabGetError)
-    def job_stats(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def job_stats(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Return statistics about the jobs performed.
 
         Args:
@@ -73,9 +70,7 @@ def job_stats(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
 
     @cli.register_custom_action("SidekiqManager")
     @exc.on_http_error(exc.GitlabGetError)
-    def compound_metrics(
-        self, **kwargs: Any
-    ) -> Union[Dict[str, Any], requests.Response]:
+    def compound_metrics(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Return all available metrics and statistics.
 
         Args:
diff --git a/gitlab/v4/objects/users.py b/gitlab/v4/objects/users.py
index 69d875ed9..fada6499c 100644
--- a/gitlab/v4/objects/users.py
+++ b/gitlab/v4/objects/users.py
@@ -3,10 +3,9 @@
 https://docs.gitlab.com/ee/api/users.html
 https://docs.gitlab.com/ee/api/projects.html#list-projects-starred-by-a-user
 """
-from typing import Any, cast, Dict, List, Optional, Union
-
-import requests
+from typing import Any, cast, List, Optional, Union
 
+import gitlab
 from gitlab import cli
 from gitlab import exceptions as exc
 from gitlab import types
@@ -188,7 +187,7 @@ def block(self, **kwargs: Any) -> Optional[bool]:
 
     @cli.register_custom_action("User")
     @exc.on_http_error(exc.GitlabFollowError)
-    def follow(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def follow(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Follow the user.
 
         Args:
@@ -206,7 +205,7 @@ def follow(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
 
     @cli.register_custom_action("User")
     @exc.on_http_error(exc.GitlabUnfollowError)
-    def unfollow(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def unfollow(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Unfollow the user.
 
         Args:
@@ -249,7 +248,7 @@ def unblock(self, **kwargs: Any) -> Optional[bool]:
 
     @cli.register_custom_action("User")
     @exc.on_http_error(exc.GitlabDeactivateError)
-    def deactivate(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def deactivate(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Deactivate the user.
 
         Args:
@@ -270,7 +269,7 @@ def deactivate(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
 
     @cli.register_custom_action("User")
     @exc.on_http_error(exc.GitlabActivateError)
-    def activate(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def activate(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Activate the user.
 
         Args:
@@ -291,7 +290,7 @@ def activate(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
 
     @cli.register_custom_action("User")
     @exc.on_http_error(exc.GitlabUserApproveError)
-    def approve(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def approve(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Approve a user creation request.
 
         Args:
@@ -309,7 +308,7 @@ def approve(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
 
     @cli.register_custom_action("User")
     @exc.on_http_error(exc.GitlabUserRejectError)
-    def reject(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def reject(self, **kwargs: Any) -> gitlab.client.HttpResponseType:
         """Reject a user creation request.
 
         Args:
@@ -327,7 +326,7 @@ def reject(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
 
     @cli.register_custom_action("User")
     @exc.on_http_error(exc.GitlabBanError)
-    def ban(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def ban(self, **kwargs: Any) -> bool:
         """Ban the user.
 
         Args:
@@ -341,14 +340,16 @@ def ban(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
             Whether the user has been banned
         """
         path = f"/users/{self.encoded_id}/ban"
-        server_data = self.manager.gitlab.http_post(path, **kwargs)
-        if server_data:
+        # NOTE: Undocumented behavior of the GitLab API is that it returns True
+        # on success.
+        server_data = cast(bool, self.manager.gitlab.http_post(path, **kwargs))
+        if server_data is True:
             self._attrs["state"] = "banned"
         return server_data
 
     @cli.register_custom_action("User")
     @exc.on_http_error(exc.GitlabUnbanError)
-    def unban(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
+    def unban(self, **kwargs: Any) -> bool:
         """Unban the user.
 
         Args:
@@ -362,8 +363,10 @@ def unban(self, **kwargs: Any) -> Union[Dict[str, Any], requests.Response]:
             Whether the user has been unbanned
         """
         path = f"/users/{self.encoded_id}/unban"
-        server_data = self.manager.gitlab.http_post(path, **kwargs)
-        if server_data:
+        # NOTE: Undocumented behavior of the GitLab API is that it returns True
+        # on success.
+        server_data = cast(bool, self.manager.gitlab.http_post(path, **kwargs))
+        if server_data is True:
             self._attrs["state"] = "active"
         return server_data
 
diff --git a/pyproject.toml b/pyproject.toml
index 43359e986..544543bc8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,6 +16,7 @@ disallow_untyped_defs = true
 no_implicit_reexport = true
 strict_equality = true
 warn_redundant_casts = true
+warn_return_any = true
 warn_unused_configs = true
 warn_unused_ignores = true
 
@@ -23,7 +24,6 @@ warn_unused_ignores = true
 # disallow_any_generics = true
 # disallow_untyped_calls = true
 # no_implicit_optional = true
-# warn_return_any = true
 
 [[tool.mypy.overrides]] # Overrides for currently untyped modules
 module = [
diff --git a/tests/functional/api/test_users.py b/tests/functional/api/test_users.py
index a099e8fb2..ba6f60cd9 100644
--- a/tests/functional/api/test_users.py
+++ b/tests/functional/api/test_users.py
@@ -3,8 +3,11 @@
 https://docs.gitlab.com/ee/api/users.html
 https://docs.gitlab.com/ee/api/users.html#delete-authentication-identity-from-user
 """
+import pytest
 import requests
 
+import gitlab.exceptions
+
 
 def test_create_user(gl, fixture_dir):
     user = gl.users.create(
@@ -45,19 +48,29 @@ def test_block_user(gl, user):
 
     # unblock again
     result = user.unblock()
-    # Trying to unblock an already blocked user returns False
+    # Trying to unblock an already un-blocked user returns False
     assert result is False
 
 
 def test_ban_user(gl, user):
-    user.ban()
+    result = user.ban()
+    assert result is True
     retrieved_user = gl.users.get(user.id)
     assert retrieved_user.state == "banned"
 
-    user.unban()
+    # ban an already banned user raises an exception
+    with pytest.raises(gitlab.exceptions.GitlabBanError):
+        user.ban()
+
+    result = user.unban()
+    assert result is True
     retrieved_user = gl.users.get(user.id)
     assert retrieved_user.state == "active"
 
+    # unban an already un-banned user raises an exception
+    with pytest.raises(gitlab.exceptions.GitlabUnbanError):
+        user.unban()
+
 
 def test_delete_user(gl, wait_for_sidekiq):
     new_user = gl.users.create(
diff --git a/tests/unit/objects/test_projects.py b/tests/unit/objects/test_projects.py
index 85bae8600..3e2f75356 100644
--- a/tests/unit/objects/test_projects.py
+++ b/tests/unit/objects/test_projects.py
@@ -431,7 +431,7 @@ def resp_start_housekeeping():
         rsps.add(
             method=responses.POST,
             url="http://localhost/api/v4/projects/1/housekeeping",
-            json="0ee4c430667fb7be8461f310",
+            json={},
             content_type="application/json",
             status=201,
         )
diff --git a/tests/unit/test_cli.py b/tests/unit/test_cli.py
index ef33b5db9..30693d995 100644
--- a/tests/unit/test_cli.py
+++ b/tests/unit/test_cli.py
@@ -24,6 +24,7 @@
 
 import pytest
 
+import gitlab.base
 from gitlab import cli
 from gitlab.exceptions import GitlabError
 
@@ -43,7 +44,7 @@ def test_gitlab_resource_to_cls(gitlab_resource, expected_class):
     def _namespace():
         pass
 
-    ExpectedClass = type(expected_class, (), {})
+    ExpectedClass = type(expected_class, (gitlab.base.RESTObject,), {})
     _namespace.__dict__[expected_class] = ExpectedClass
 
     assert cli.gitlab_resource_to_cls(gitlab_resource, _namespace) == ExpectedClass