diff --git a/lib/db.py b/lib/db.py
index 5c61ad1..2d2b407 100644
--- a/lib/db.py
+++ b/lib/db.py
@@ -146,6 +146,10 @@ class DB:
                REFERENCES requests (id)""",
             "UPDATE scheme SET version=10",
         )
+        schemes[11] = (
+            "create index request_number_idx on revisions (request_number);",
+            "UPDATE scheme SET version=11",
+        )
         schema_version = self.schema_version()
         if (schema_version + 1) not in schemes:
             return