diff --git a/kernel/proc/procgroup.c b/kernel/proc/procgroup.c
index 7926fcf..c47b089 100644
--- a/kernel/proc/procgroup.c
+++ b/kernel/proc/procgroup.c
@@ -145,7 +145,6 @@ struct procgroup* procgroup_create (void) {
 
   memset (procgroup, 0, sizeof (*procgroup));
 
-  procgroup->refs = 0;
   procgroup->memb_proc_tree = NULL;
   procgroup->lock = SPIN_LOCK_INIT;
   procgroup->pgid = atomic_fetch_add (&pgids, 1);
@@ -171,7 +170,6 @@ void procgroup_attach (struct procgroup* procgroup, struct proc* proc) {
 
   rbtree_insert (struct proc, &procgroup->memb_proc_tree, &proc->procgroup_memb_tree_link,
                  procgroup_memb_tree_link, pid);
-  atomic_fetch_add (&procgroup->refs, 1);
 
   spin_unlock (&proc->lock);
   spin_unlock (&procgroup->lock);
@@ -183,12 +181,12 @@ void procgroup_detach (struct procgroup* procgroup, struct proc* proc,
   spin_lock (&proc->lock);
 
   rbtree_delete (&procgroup->memb_proc_tree, &proc->procgroup_memb_tree_link);
-  int refs = atomic_fetch_sub (&procgroup->refs, 1);
+  struct rb_node_link* memb_tree = procgroup->memb_proc_tree;
 
   spin_unlock (&proc->lock);
   spin_unlock (&procgroup->lock);
 
-  if (refs == 1) {
+  if (memb_tree == NULL) {
     spin_lock (&procgroup_tree_lock);
     spin_lock (&procgroup->lock);
 
diff --git a/kernel/proc/procgroup.h b/kernel/proc/procgroup.h
index b283909..26cb150 100644
--- a/kernel/proc/procgroup.h
+++ b/kernel/proc/procgroup.h
@@ -25,9 +25,7 @@ struct procgroup {
   struct rb_node_link procgroup_tree_link;
   struct rb_node_link* memb_proc_tree;
   spin_lock_t lock;
-  atomic_int refs;
   struct rb_node_link* resource_tree;
-  atomic_int sys_rids;
   struct pd pd;
   struct list_node_link* mappings;
   uintptr_t map_base;