diff --git a/atlas/service/doctype/ipv6_router_server/ipv6_router_server.py b/atlas/service/doctype/ipv6_router_server/ipv6_router_server.py
index 4db0d62ee..40da70fb6 100644
--- a/atlas/service/doctype/ipv6_router_server/ipv6_router_server.py
+++ b/atlas/service/doctype/ipv6_router_server/ipv6_router_server.py
@@ -3,6 +3,7 @@
 
 from __future__ import annotations
 
+import ipaddress
 from contextlib import contextmanager
 from typing import TYPE_CHECKING, Any
 
@@ -128,6 +129,9 @@ def archive(self) -> None:
 			router.save(ignore_permissions=True)
 			if pool:
 				pool.gateway = None
+				# A direct provider pool hands out its whole prefix.
+				if pool.source == "Provider":
+					pool.allocation_prefix_length = ipaddress.ip_network(pool.prefix, strict=False).prefixlen
 				pool.save(ignore_permissions=True)
 
 		frappe.msgprint(_("IPv6 Router Server {0} is archived.").format(self.name))
diff --git a/atlas/service/doctype/ipv6_router_server/test_ipv6_router_server.py b/atlas/service/doctype/ipv6_router_server/test_ipv6_router_server.py
index c062526a5..3c1a0d0e7 100644
--- a/atlas/service/doctype/ipv6_router_server/test_ipv6_router_server.py
+++ b/atlas/service/doctype/ipv6_router_server/test_ipv6_router_server.py
@@ -145,3 +145,19 @@ def test_archive_queues_the_pool_detach_instead_of_running_it(self) -> None:
 		pool.queue_reconcile.assert_called_once_with()
 		pool.reconcile.assert_not_called()
 		self.assertEqual(router.status, "Archived")
+
+	def test_archive_returns_a_provider_pool_to_one_allocation(self) -> None:
+		pool = MagicMock(source="Provider", prefix="2001:db8::/80", allocation_prefix_length=128)
+		router = MagicMock(status="Failed", virtual_machine=None, pool=pool)
+		with (
+			patch.object(router_module, "_validate_system_manager"),
+			patch.object(router_module, "ipv6_router_lifecycle_lock", return_value=nullcontext()),
+			patch.object(router_module.frappe, "get_doc", return_value=router),
+			patch.object(router_module.frappe.db, "exists", return_value=False),
+			patch.object(router_module.frappe, "msgprint"),
+		):
+			IPv6RouterServer.archive(SimpleNamespace(doctype="IPv6 Router Server", name="ipv6-router-001"))
+
+		self.assertIsNone(pool.gateway)
+		self.assertEqual(pool.allocation_prefix_length, 80)
+		pool.save.assert_called_once_with(ignore_permissions=True)