diff --git a/src/libraries/datatype/datatype.ml b/src/libraries/datatype/datatype.ml
index 7431ed5987cbde1c2e03734c1fdcf705344a0b58..a9b4e22ea1c8053c2506b72d19f5b8193f4c41d4 100644
--- a/src/libraries/datatype/datatype.ml
+++ b/src/libraries/datatype/datatype.ml
@@ -1676,7 +1676,7 @@ module With_collections(X: S)(Info: Functor_info) = struct
 
   module Set =
     Set
-      (Stdlib.Set.Make(D))
+      (Transitioning.Stdlib.Set.Make(D))
       (D)
       (struct let module_name = Info.module_name ^ ".Set" end)
 
diff --git a/src/libraries/stdlib/transitioning.ml.in b/src/libraries/stdlib/transitioning.ml.in
index 8ceacaa401aecdcf0ef65311829266a1c525ecc7..5c42724fd50308e3e4b34b15f29d00b2cff225b6 100644
--- a/src/libraries/stdlib/transitioning.ml.in
+++ b/src/libraries/stdlib/transitioning.ml.in
@@ -30,6 +30,7 @@ module Stdlib = struct
   let min_int = min_int
   let max_int = max_int
   let flush = flush
+  module Set = Set
   module Map = Map
 end
 
diff --git a/src/libraries/stdlib/transitioning.mli b/src/libraries/stdlib/transitioning.mli
index 5ae8e71271b63319184ac0931bd2775607c5304a..bda303904a08c406c0651743ca67aebd217c7628 100644
--- a/src/libraries/stdlib/transitioning.mli
+++ b/src/libraries/stdlib/transitioning.mli
@@ -43,6 +43,7 @@ module Stdlib: sig
   val min_int: int
   val max_int: int
   val flush: out_channel -> unit
+  module Set: module type of Set
   module Map: module type of Map
 end
 
diff --git a/src/plugins/pdg/build.ml b/src/plugins/pdg/build.ml
index 14bacfb126e18597c2f5602cee4358cd56522e88..6dd4c17e41dcc32a28c7897e3d0003f272ccb0d2 100644
--- a/src/plugins/pdg/build.ml
+++ b/src/plugins/pdg/build.ml
@@ -45,7 +45,7 @@ exception Err_Bot of string
 
 (** set of nodes of the graph *)
 module BoolNodeSet =
-  Stdlib.Set.Make(Datatype.Pair(Datatype.Bool)(PdgTypes.Node))
+  Transitioning.Stdlib.Set.Make(Datatype.Pair(Datatype.Bool)(PdgTypes.Node))
 
 let pretty_node ?(key=false) fmt n = 
   PdgTypes.Node.pretty fmt n;