diff --git a/src/_zkapauthorizer/tests/test_storage_protocol.py b/src/_zkapauthorizer/tests/test_storage_protocol.py
index f821ad5278814518ffa196b6c8e47e206f2546d1..d5fc174897d58d9fa97c777e1c6da4813aa8eab1 100644
--- a/src/_zkapauthorizer/tests/test_storage_protocol.py
+++ b/src/_zkapauthorizer/tests/test_storage_protocol.py
@@ -394,7 +394,7 @@ class ShareTests(TestCase):
         self.assertThat(
             wrote,
             Equals(True),
-            u"Server rejected a write to a new mutable storage index",
+            u"Server rejected a write to a new mutable slot",
         )
 
         self.assertThat(