diff --git a/src/core/route.mli b/src/core/route.mli
index 29d54e3d..69bc8668 100644
--- a/src/core/route.mli
+++ b/src/core/route.mli
@@ -54,7 +54,10 @@ val to_string : _ t -> string
     @since 0.7 *)
 
 val to_url : ('a, string) t -> 'a
-(** [to_url route args] takes a route, and turns it into a URL path. *)
+
+(** [to_url route args] takes a route, and turns it into a URL path.
+    @since NEXT_RELEASE *)
+
 
 module Private_ : sig
   val eval : string list -> ('a, 'b) t -> 'a -> 'b option