diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py
index e98618e45657..eea0d1c8fbcc 100644
--- a/synapse/storage/background_updates.py
+++ b/synapse/storage/background_updates.py
@@ -760,7 +760,7 @@ def create_index_psql(conn: Connection) -> None:
 
                 # override the global statement timeout to avoid accidentally squashing
                 # a long-running index creation process
-                timeout_sql = "SET LOCAL statement timeout = 0"
+                timeout_sql = "SET LOCAL statement_timeout = 0"
                 c.execute(timeout_sql)
 
                 sql = (