2 files changed, 3 insertions, 1 deletions

diff --git a/kernel/names.ml b/kernel/names.ml
index e6c5686ed9..7cb8dc4c41 100644
--- a/kernel/names.ml
+++ b/kernel/names.ml
@@ -122,6 +122,7 @@ type variable = Id.t
 
 type module_ident = Id.t
 
+module ModIdset = Id.Set
 module ModIdmap = Id.Map
 
 (** {6 Directory paths = section names paths } *)
diff --git a/kernel/names.mli b/kernel/names.mli
index 16d0ae5d04..8164677214 100644
--- a/kernel/names.mli
+++ b/kernel/names.mli
@@ -79,7 +79,8 @@ type name = Name.t = Name of Id.t | Anonymous
 type variable = Id.t
 type module_ident = Id.t
 
-module ModIdmap : Map.S with type key = module_ident
+module ModIdset : Set.S with type elt = module_ident
+module ModIdmap : Map.ExtS with type key = module_ident and module Set := ModIdset
 
 (** {6 Directory paths = section names paths } *)