diff --git a/internal/caching/cache_roomservernids.go b/internal/caching/cache_roomservernids.go
index d1d306d17..da6d19b5a 100644
--- a/internal/caching/cache_roomservernids.go
+++ b/internal/caching/cache_roomservernids.go
@@ -25,9 +25,9 @@ type RoomServerNIDsCache interface {
 }
 
 func (c Caches) GetRoomServerRoomID(roomNID types.RoomNID) (string, bool) {
-	return c.RoomServerRoomIDs.Get(roomNID)
+	return c.RoomServerRoomIDs.Get(int64(roomNID))
 }
 
 func (c Caches) StoreRoomServerRoomID(roomNID types.RoomNID, roomID string) {
-	c.RoomServerRoomIDs.Set(roomNID, roomID)
+	c.RoomServerRoomIDs.Set(int64(roomNID), roomID)
 }
diff --git a/internal/caching/caches.go b/internal/caching/caches.go
index 4d94e7321..1b456717c 100644
--- a/internal/caching/caches.go
+++ b/internal/caching/caches.go
@@ -14,7 +14,7 @@ type Caches struct {
 	RoomVersions       Cache[string, gomatrixserverlib.RoomVersion]
 	ServerKeys         Cache[string, gomatrixserverlib.PublicKeyLookupResult]
 	RoomServerRoomNIDs Cache[string, types.RoomNID]
-	RoomServerRoomIDs  Cache[types.RoomNID, string]
+	RoomServerRoomIDs  Cache[int64, string]
 	RoomInfos          Cache[string, types.RoomInfo]
 	FederationPDUs     Cache[int64, *gomatrixserverlib.HeaderedEvent]
 	FederationEDUs     Cache[int64, *gomatrixserverlib.EDU]
@@ -31,7 +31,7 @@ type Cache[K keyable, T any] interface {
 
 type keyable interface {
 	// from https://github.com/dgraph-io/ristretto/blob/8e850b710d6df0383c375ec6a7beae4ce48fc8d5/z/z.go#L34
-	~uint64 | ~string | ~[]byte | ~byte | ~int | ~int32 | ~uint32 | ~int64
+	uint64 | string | []byte | byte | int | int32 | uint32 | int64
 }
 
 type costable interface {
diff --git a/internal/caching/impl_ristretto.go b/internal/caching/impl_ristretto.go
index 291b07335..0758b5dbb 100644
--- a/internal/caching/impl_ristretto.go
+++ b/internal/caching/impl_ristretto.go
@@ -38,7 +38,7 @@ func NewRistrettoCache(maxCost CacheSize, enablePrometheus bool) (*Caches, error
 			Name:    "server_keys",
 			Mutable: true,
 		},
-		RoomServerRoomIDs: &RistrettoCachePartition[types.RoomNID, string]{
+		RoomServerRoomIDs: &RistrettoCachePartition[int64, string]{
 			cache: cache,
 			Name:  "room_ids",
 		},