diff --git a/rest_framework/pagination.py b/rest_framework/pagination.py
index 87ff7d3d6..91da73de6 100644
--- a/rest_framework/pagination.py
+++ b/rest_framework/pagination.py
@@ -198,7 +198,7 @@ class PageNumberPagination(BasePagination):
             return None
 
         paginator = self.django_paginator_class(queryset, page_size)
-        page_number = self.get_page_number(request)
+        page_number = self.get_page_number(request, paginator)
 
         try:
             self.page = paginator.page(page_number)
@@ -215,7 +215,7 @@ class PageNumberPagination(BasePagination):
         self.request = request
         return list(self.page)
 
-    def get_page_number(self, request):
+    def get_page_number(self, request, paginator):
         page_number = request.query_params.get(self.page_query_param, 1)
         if page_number in self.last_page_strings:
             page_number = paginator.num_pages