diff --git a/radis/core/mixins.py b/radis/core/mixins.py
index 744b0c3e..fd259f4f 100644
--- a/radis/core/mixins.py
+++ b/radis/core/mixins.py
@@ -142,6 +142,9 @@ def get(
 
     def get_context_data(self: PageSizeSelectMixinProtocol, **kwargs):
         context = super().get_context_data(**kwargs)
-        pages_sizes = [50, 100, 250, 500] if not self.page_sizes else self.page_sizes
-        context["page_size_select"] = PageSizeSelectForm(self.request.GET, pages_sizes)
+
+        if self.page_sizes is None:
+            self.page_sizes = [50, 100, 250, 500]
+        context["page_size_select"] = PageSizeSelectForm(self.request.GET, self.page_sizes)
+
         return context