diff --git a/synapse/storage/data_stores/main/end_to_end_keys.py b/synapse/storage/data_stores/main/end_to_end_keys.py
index e139c14769..d9ef671988 100644
--- a/synapse/storage/data_stores/main/end_to_end_keys.py
+++ b/synapse/storage/data_stores/main/end_to_end_keys.py
@@ -383,10 +383,11 @@ class EndToEndKeyWorkerStore(SQLBaseStore):
                 "SELECT target_user_id, key_id, signature "
                 "  FROM e2e_cross_signing_signatures "
                 " WHERE user_id = ?"
-                "   AND (target_user_id, target_device_id) IN (VALUES %s)"
-            ) % (",".join("(?,?)" for d in devices))
+                "   AND (%s)"
+            ) % (" OR ".join("(target_user_id = ? AND target_device_id = ?)" for d in devices))
             query_params = [from_user_id]
             for item in devices.items():
+                # item is a (user_id, device_id) tuple
                 query_params.extend(item)
 
             txn.execute(sql, query_params)