diff --git a/gitlab/base.py b/gitlab/base.py
index aa18dcfd7..7f685425a 100644
--- a/gitlab/base.py
+++ b/gitlab/base.py
@@ -302,7 +302,7 @@ def next_page(self) -> Optional[int]:
         return self._list.next_page
 
     @property
-    def per_page(self) -> int:
+    def per_page(self) -> Optional[int]:
         """The number of items per page."""
         return self._list.per_page
 
diff --git a/gitlab/client.py b/gitlab/client.py
index a4c58313a..9d1eebdd9 100644
--- a/gitlab/client.py
+++ b/gitlab/client.py
@@ -1039,11 +1039,9 @@ def next_page(self) -> Optional[int]:
         return int(self._next_page) if self._next_page else None
 
     @property
-    def per_page(self) -> int:
+    def per_page(self) -> Optional[int]:
         """The number of items per page."""
-        if TYPE_CHECKING:
-            assert self._per_page is not None
-        return int(self._per_page)
+        return int(self._per_page) if self._per_page is not None else None
 
     # NOTE(jlvillal): When a query returns more than 10,000 items, GitLab doesn't return
     # the headers 'x-total-pages' and 'x-total'. In those cases we return None.