diff --git a/src/lib.ml b/src/lib.ml
index 97caa61f..f15a49dd 100644
--- a/src/lib.ml
+++ b/src/lib.ml
@@ -814,16 +814,26 @@ and resolve_user_deps db deps ~allow_private_deps ~pps ~stack =
         closure_with_overlap_checks None pps ~stack
       in
       let deps =
+        let rec check_runtime_deps acc pps = function
+          | [] -> loop acc pps
+          | lib :: ppx_rts ->
+            check_private_deps lib ~loc ~allow_private_deps >>= fun rt ->
+            check_runtime_deps (rt :: acc) pps ppx_rts
+        and loop acc = function
+          | [] -> Ok acc
+          | pp :: pps ->
+            pp.ppx_runtime_deps >>= fun rt_deps ->
+            check_runtime_deps acc pps rt_deps
+        in
         deps >>= fun deps ->
-        pps >>= Result.List.concat_map ~f:(fun pp -> pp.ppx_runtime_deps)
-        >>| List.rev_append deps
-        >>= Result.List.map ~f:(check_private_deps ~loc ~allow_private_deps)
+        pps  >>= fun pps  ->
+        loop deps pps
       in
       (deps, pps)
   in
   (deps, pps, resolved_selects)
 
-and closure_with_overlap_checks db ts ~stack =
+  and closure_with_overlap_checks db ts ~stack =
   let visited = ref String.Map.empty in
   let res = ref [] in
   let orig_stack = stack in