diff --git a/src/fellchensammlung/views.py b/src/fellchensammlung/views.py
index 093fe1f..eb582f8 100644
--- a/src/fellchensammlung/views.py
+++ b/src/fellchensammlung/views.py
@@ -697,8 +697,13 @@ def list_rescue_organizations(request, template='fellchensammlung/animal-shelter
     paginator = Paginator(rescue_organizations, 10)
 
     page_number = request.GET.get("page")
-    if page_number is None or not isinstance(page_number, int):
+    if page_number is None:
         page_number = 1
+    else:
+        try:
+            page_number = int(page_number)
+        except ValueError:
+            page_number = 1
 
     rescue_organizations_to_list = paginator.get_page(page_number)
     context = {"rescue_organizations_to_list": rescue_organizations_to_list,