diff --git a/github/Installation.py b/github/Installation.py
index 46119c0b..a7c3f66a 100644
--- a/github/Installation.py
+++ b/github/Installation.py
@@ -23,8 +23,9 @@
 # along with PyGithub. If not, see <http://www.gnu.org/licenses/>.             #
 #                                                                              #
 ################################################################################
+from __future__ import annotations
 
-from typing import Any, Dict
+from typing import TYPE_CHECKING, Any
 
 import github.Authorization
 import github.Event
@@ -37,19 +38,30 @@ import github.PaginatedList
 import github.Plan
 import github.Repository
 import github.UserKey
+from github import Consts
 from github.Auth import AppAuth
+from github.GithubObject import Attribute, NonCompletableGithubObject, NotSet
+from github.PaginatedList import PaginatedList
+from github.Requester import Requester
 
-from . import Consts
+if TYPE_CHECKING:
+    from github.MainClass import Github
 
 INTEGRATION_PREVIEW_HEADERS = {"Accept": Consts.mediaTypeIntegrationPreview}
 
 
-class Installation(github.GithubObject.NonCompletableGithubObject):
+class Installation(NonCompletableGithubObject):
     """
     This class represents Installations. The reference can be found here https://docs.github.com/en/rest/reference/apps#installations
     """
 
-    def __init__(self, requester, headers, attributes, completed):
+    def __init__(
+        self,
+        requester: Requester,
+        headers: dict[str, str | int],
+        attributes: Any,
+        completed: bool,
+    ) -> None:
         super().__init__(requester, headers, attributes, completed)
 
         auth = self._requester.auth if self._requester is not None else None
@@ -59,48 +71,41 @@ class Installation(github.GithubObject.NonCompletableGithubObject):
             auth = auth.get_installation_auth(self.id, requester=self._requester)
             self._requester = self._requester.withAuth(auth)
 
+    def _initAttributes(self) -> None:
+        self._id: Attribute[int] = NotSet
+        self._app_id: Attribute[int] = NotSet
+        self._target_id: Attribute[int] = NotSet
+        self._target_type: Attribute[str] = NotSet
+
     def __repr__(self) -> str:
         return self.get__repr__({"id": self._id.value})
 
-    def get_github_for_installation(self):
+    def get_github_for_installation(self) -> Github:
         return github.Github(**self._requester.kwargs)
 
     @property
-    def id(self):
-        """
-        :type: integer
-        """
+    def id(self) -> int:
         return self._id.value
 
     @property
-    def app_id(self):
-        """
-        :type: integer
-        """
+    def app_id(self) -> int:
         return self._app_id.value
 
     @property
-    def target_id(self):
-        """
-        :type: integer
-        """
+    def target_id(self) -> int:
         return self._target_id.value
 
     @property
-    def target_type(self):
-        """
-        :type: string
-        """
+    def target_type(self) -> str:
         return self._target_type.value
 
-    def get_repos(self):
+    def get_repos(self) -> PaginatedList[github.Repository.Repository]:
         """
         :calls: `GET /installation/repositories <https://docs.github.com/en/rest/reference/integrations/installations#list-repositories>`_
-        :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.Repository.Repository`
         """
-        url_parameters = dict()
+        url_parameters: dict[str, Any] = {}
 
-        return github.PaginatedList.PaginatedList(
+        return PaginatedList(
             contentClass=github.Repository.Repository,
             requester=self._requester,
             firstUrl="/installation/repositories",
@@ -109,13 +114,7 @@ class Installation(github.GithubObject.NonCompletableGithubObject):
             list_item="repositories",
         )
 
-    def _initAttributes(self) -> None:
-        self._id = github.GithubObject.NotSet
-        self._app_id = github.GithubObject.NotSet
-        self._target_id = github.GithubObject.NotSet
-        self._target_type = github.GithubObject.NotSet
-
-    def _useAttributes(self, attributes: Dict[str, Any]) -> None:
+    def _useAttributes(self, attributes: dict[str, Any]) -> None:
         if "id" in attributes:  # pragma no branch
             self._id = self._makeIntAttribute(attributes["id"])
         if "app_id" in attributes:  # pragma no branch
diff --git a/github/Installation.pyi b/github/Installation.pyi
deleted file mode 100644
index 46ec8bcd..00000000
--- a/github/Installation.pyi
+++ /dev/null
@@ -1,14 +0,0 @@
-from typing import Any, Dict
-
-import github
-from github.GithubObject import NonCompletableGithubObject
-from github.PaginatedList import PaginatedList
-from github.Repository import Repository
-
-class Installation(NonCompletableGithubObject):
-    def _initAttributes(self) -> None: ...
-    def _useAttributes(self, attributes: Dict[str, Any]) -> None: ...
-    def get_github_for_installation(self) -> github.Github: ...
-    @property
-    def id(self) -> int: ...
-    def get_repos(self) -> PaginatedList[Repository]: ...