diff --git a/synapse/storage/databases/main/transactions.py b/synapse/storage/databases/main/transactions.py

index 6c299cafa5..4b78b4d098 100644
--- a/synapse/storage/databases/main/transactions.py
+++ b/synapse/storage/databases/main/transactions.py
@@ -560,3 +560,14 @@ class TransactionWorkerStore(CacheInvalidationWorkerStore):
         return await self.db_pool.runInteraction(
             "get_destinations_paginate_txn", get_destinations_paginate_txn
         )
+
+    async def is_destination_known(self, destination: str) -> bool:
+        """Check if a destination is known to the server."""
+        result = await self.db_pool.simple_select_one_onecol(
+            table="destinations",
+            keyvalues={"destination": destination},
+            retcol="1",
+            allow_none=True,
+            desc="is_destination_known",
+        )
+        return bool(result)