diff --git a/proposals/4103-threaded-read-receipt-sync-filter.md b/proposals/4103-threaded-read-receipt-sync-filter.md
index 47358cc7..32f6c438 100644
--- a/proposals/4103-threaded-read-receipt-sync-filter.md
+++ b/proposals/4103-threaded-read-receipt-sync-filter.md
@@ -74,4 +74,4 @@ can always expose threadedness as metadata to aid this if it were to happen.
 
 ## Unstable prefix
 
-`threaded_read_receipts` should be namespaced as `org.matrix.msc4013.threaded_read_receipts` while unstable.
+`threaded_read_receipts` should be namespaced as `org.matrix.msc4103.threaded_read_receipts` while unstable.