diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 5b8dd98a230e442c1ec46adc968acb60dfdb74ae..b88d4186cd7ac2733c3adf231d5b4daa4e14b0a9 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -155,7 +155,7 @@ int ptrace_attach(struct task_struct *task)
 	retval = -EPERM;
 	if (task->pid <= 1)
 		goto bad;
-	if (task == current)
+	if (task->tgid == current->tgid)
 		goto bad;
 	/* the same process cannot be attached many times */
 	if (task->ptrace & PT_PTRACED)