diff --git a/synapse/storage/data_stores/main/schema/delta/56/event_labels.sql b/synapse/storage/data_stores/main/schema/delta/56/event_labels.sql
index 323d79741..9550b0ada 100644
--- a/synapse/storage/data_stores/main/schema/delta/56/event_labels.sql
+++ b/synapse/storage/data_stores/main/schema/delta/56/event_labels.sql
@@ -17,4 +17,6 @@ CREATE TABLE IF NOT EXISTS event_labels (
     event_id TEXT,
     label TEXT,
     PRIMARY KEY(event_id, label)
-);
\ No newline at end of file
+);
+
+CREATE INDEX event_labels_label_idx ON event_labels(label);