diff --git a/ruma-client-api/src/r0/backup.rs b/ruma-client-api/src/r0/backup.rs
index aa3a78ce..7840f380 100644
--- a/ruma-client-api/src/r0/backup.rs
+++ b/ruma-client-api/src/r0/backup.rs
@@ -1,4 +1,5 @@
 //! Endpoints for server-side key backups.
+#![cfg(feature = "unstable-pre-spec")]
 
 pub mod add_backup_key_session;
 pub mod add_backup_key_sessions;