diff --git a/src/build.ml b/src/build.ml
index 4b5078c9..6a19d059 100644
--- a/src/build.ml
+++ b/src/build.ml
@@ -211,7 +211,7 @@ let prog_and_args ?(dir=Path.root) prog args =
   (get_prog prog &&&
    (arr (Arg_spec.expand ~dir args)
     >>>
-    dyn_paths (arr (fun (_args, deps) -> Path.Set.to_list deps))
+    dyn_path_set (arr (fun (_args, deps) -> deps))
     >>>
     arr fst))
 
diff --git a/src/super_context.ml b/src/super_context.ml
index 9d7c3782..141c6aa6 100644
--- a/src/super_context.ml
+++ b/src/super_context.ml
@@ -830,11 +830,11 @@ module Action = struct
           | Ok path    -> path
           | Error fail -> Action.Prog.Not_found.raise fail))
       >>>
-      Build.dyn_paths (Build.arr (fun action ->
+      Build.dyn_path_set (Build.arr (fun action ->
         let { Action.Infer.Outcome.deps; targets = _ } =
           Action.Infer.infer action
         in
-        Pset.to_list deps))
+        deps))
       >>>
       Build.action_dyn () ~dir ~targets
     in