diff --git a/rest_framework/routers.py b/rest_framework/routers.py
index 2cf3338e9..4ee3686ea 100644
--- a/rest_framework/routers.py
+++ b/rest_framework/routers.py
@@ -280,6 +280,7 @@ class NestedSimpleRouter(SimpleRouter):
         self.parent_router = parent_router
         self.parent_prefix = parent_prefix
         self.nest_count = getattr(parent_router, 'nest_count', 0) +1
+        self.nest_prefix = kwargs.pop('lookup', 'nested_%i' % self.nest_count) + '_'
         super(NestedSimpleRouter, self).__init__(*args, **kwargs)
 
         parent_registry = filter(lambda registered: registered[0] == self.parent_prefix, self.parent_router.registry)
@@ -290,8 +291,7 @@ class NestedSimpleRouter(SimpleRouter):
             raise RuntimeError('parent registered resource not found')
 
         nested_routes = []
-        nest_prefix = 'nested_%i' % self.nest_count
-        parent_lookup_regex = parent_router.get_lookup_regex(parent_viewset, nest_prefix)
+        parent_lookup_regex = parent_router.get_lookup_regex(parent_viewset, self.nest_prefix)
         for route in self.routes:
             route_contents = route.__dict__
             parent_regex = '{parent_prefix}/{parent_lookup_regex}/'.format(parent_prefix=parent_prefix, parent_lookup_regex=parent_lookup_regex)