diff --git a/kernel/proc.c b/kernel/proc.c
index d88e453..54c965d 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -401,7 +401,7 @@ wait(uint64 addr)
           if(addr != 0 && copyout(p->pagetable, addr, (char *)&np->xstate,
                                   sizeof(np->xstate)) < 0) {
             release(&np->lock);
-            release(&p->lock);
+            release(&proc_tree_lock);
             return -1;
           }
           freeproc(np);