diff --git a/src/gen_rules.ml b/src/gen_rules.ml
index 2b9e399e..bb5141ac 100644
--- a/src/gen_rules.ml
+++ b/src/gen_rules.ml
@@ -17,11 +17,6 @@ module Gen(P : Install_rules.Params) = struct
   let sctx = P.sctx
   let ctx = SC.context sctx
 
-  let stanzas_per_dir =
-    List.map (SC.stanzas sctx) ~f:(fun stanzas ->
-      (stanzas.SC.Dir_with_jbuild.ctx_dir, stanzas))
-    |> Path.Map.of_list_exn
-
   (* +-----------------------------------------------------------------+
      | Interpretation of [modules] fields                              |
      +-----------------------------------------------------------------+ *)
@@ -195,7 +190,7 @@ module Gen(P : Install_rules.Params) = struct
 
     (* As a side-effect, setup user rules and copy_files rules. *)
     let load_text_files ~dir =
-      match Path.Map.find stanzas_per_dir dir with
+      match SC.stanzas_in sctx ~dir with
       | None -> String.Set.empty
       | Some { stanzas; src_dir; scope; _ } ->
         (* Interpret a few stanzas in order to determine the list of
@@ -1006,7 +1001,7 @@ module Gen(P : Install_rules.Params) = struct
      | "_doc" :: rest -> Odoc.gen_rules rest ~dir
      | ".ppx"  :: rest -> Preprocessing.gen_rules sctx rest
      | _ ->
-       match Path.Map.find stanzas_per_dir dir with
+       match SC.stanzas_in sctx ~dir with
        | Some x -> gen_rules x
        | None ->
          if components <> [] &&
diff --git a/src/super_context.ml b/src/super_context.ml
index c3459b86..973c4bfc 100644
--- a/src/super_context.ml
+++ b/src/super_context.ml
@@ -40,6 +40,7 @@ type t =
   ; public_libs                      : Lib.DB.t
   ; installed_libs                   : Lib.DB.t
   ; stanzas                          : Dir_with_jbuild.t list
+  ; stanzas_per_dir                  : Dir_with_jbuild.t Path.Map.t
   ; packages                         : Package.t Package.Name.Map.t
   ; file_tree                        : File_tree.t
   ; artifacts                        : Artifacts.t
@@ -55,6 +56,7 @@ type t =
 
 let context t = t.context
 let stanzas t = t.stanzas
+let stanzas_in t ~dir = Path.Map.find t.stanzas_per_dir dir
 let packages t = t.packages
 let libs_by_package t = t.libs_by_package
 let artifacts t = t.artifacts
@@ -248,6 +250,11 @@ let create
         ; kind
         })
   in
+  let stanzas_per_dir =
+    List.map stanzas ~f:(fun stanzas ->
+      (stanzas.Dir_with_jbuild.ctx_dir, stanzas))
+    |> Path.Map.of_list_exn
+  in
   let stanzas_to_consider_for_install =
     if not external_lib_deps_mode then
       List.concat_map stanzas ~f:(fun { ctx_dir; stanzas; scope; kind; _ } ->
@@ -305,6 +312,7 @@ let create
     ; public_libs
     ; installed_libs
     ; stanzas
+    ; stanzas_per_dir
     ; packages
     ; file_tree
     ; stanzas_to_consider_for_install
diff --git a/src/super_context.mli b/src/super_context.mli
index 40bf02d8..02e630f6 100644
--- a/src/super_context.mli
+++ b/src/super_context.mli
@@ -43,6 +43,7 @@ val create
 
 val context   : t -> Context.t
 val stanzas   : t -> Dir_with_jbuild.t list
+val stanzas_in : t -> dir:Path.t -> Dir_with_jbuild.t option
 val packages  : t -> Package.t Package.Name.Map.t
 val libs_by_package : t -> (Package.t * Lib.Set.t) Package.Name.Map.t
 val file_tree : t -> File_tree.t