diff --git a/src/core/CCRef.mli b/src/core/CCRef.mli
index 475c0d97..e0d74cd6 100644
--- a/src/core/CCRef.mli
+++ b/src/core/CCRef.mli
@@ -24,7 +24,8 @@ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *)
 
-(** {1 References} *)
+(** {1 References}
+@since NEXT_RELEASE *)
 
 type 'a print = Format.formatter -> 'a -> unit
 type 'a pp = Buffer.t -> 'a -> unit
diff --git a/src/core/CCSet.mli b/src/core/CCSet.mli
index cc396ddc..9261505b 100644
--- a/src/core/CCSet.mli
+++ b/src/core/CCSet.mli
@@ -24,7 +24,8 @@ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *)
 
-(** {1 Wrapper around Set} *)
+(** {1 Wrapper around Set}
+@since NEXT_RELEASE *)
 
 type 'a sequence = ('a -> unit) -> unit
 type 'a printer = Buffer.t -> 'a -> unit