diff --git a/opal/mca/hwloc/hwloc191/hwloc/src/topology-x86.c b/opal/mca/hwloc/hwloc191/hwloc/src/topology-x86.c
index e1db138e32..18ba6e8529 100644
--- a/opal/mca/hwloc/hwloc191/hwloc/src/topology-x86.c
+++ b/opal/mca/hwloc/hwloc191/hwloc/src/topology-x86.c
@@ -401,6 +401,7 @@ static void summarize(hwloc_topology_t topology, struct procinfo *infos, unsigne
   unsigned i, j, l, level, type;
   unsigned nbsockets = 0;
   int one = -1;
+  unsigned next_group_depth = topology->next_group_depth;
 
   for (i = 0; i < nbprocs; i++)
     if (infos[i].present) {
@@ -580,9 +581,12 @@ static void summarize(hwloc_topology_t topology, struct procinfo *infos, unsigne
 	      hwloc_bitmap_clr(unknowns_cpuset, j);
 	    }
 	  }
-	  unknown_obj = hwloc_alloc_setup_object(HWLOC_OBJ_MISC, unknownid);
+	  unknown_obj = hwloc_alloc_setup_object(HWLOC_OBJ_GROUP, unknownid);
 	  unknown_obj->cpuset = unknown_cpuset;
 	  unknown_obj->os_level = level;
+	  unknown_obj->attr->group.depth = topology->next_group_depth + level;
+	  if (next_group_depth <= topology->next_group_depth + level)
+	    next_group_depth = topology->next_group_depth + level + 1;
 	  hwloc_debug_2args_bitmap("os unknown%d %u has cpuset %s\n",
 	      level, unknownid, unknown_cpuset);
 	  hwloc_insert_object_by_cpuset(topology, unknown_obj);
@@ -714,6 +718,7 @@ static void summarize(hwloc_topology_t topology, struct procinfo *infos, unsigne
   }
 
   hwloc_bitmap_free(complete_cpuset);
+  topology->next_group_depth = next_group_depth;
 }
 
 static int