Index: head/sys/compat/linux/linux_fork.c
===================================================================
--- head/sys/compat/linux/linux_fork.c
+++ head/sys/compat/linux/linux_fork.c
@@ -40,6 +40,7 @@
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
+#include <sys/ptrace.h>
 #include <sys/racct.h>
 #include <sys/sched.h>
 #include <sys/syscallsubr.h>
@@ -352,6 +353,9 @@
 	thread_unlock(td);
 	if (P_SHOULDSTOP(p))
 		newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
+	
+	if (p->p_ptevents & PTRACE_LWP)
+		newtd->td_dbgflags |= TDB_BORN;
 	PROC_UNLOCK(p);
 
 	tidhash_add(newtd);