diff --git a/proposals/xxxx-copy-room-type-on-upgrade.md b/proposals/3818-copy-room-type-on-upgrade.md
similarity index 95%
rename from proposals/xxxx-copy-room-type-on-upgrade.md
rename to proposals/3818-copy-room-type-on-upgrade.md
index 0365e7bcb29..8e01f77ea11 100644
--- a/proposals/xxxx-copy-room-type-on-upgrade.md
+++ b/proposals/3818-copy-room-type-on-upgrade.md
@@ -1,4 +1,4 @@
-# MSCXXXX: Copy room type on upgrade.
+# MSC3818: Copy room type on upgrade
 
 There can never be enough templates in the world, and MSCs shouldn't be any different. The level
 of detail expected of proposals can be unclear - this is what this example proposal (which doubles