Index: sys/compat/linux/linux_misc.c
===================================================================
--- sys/compat/linux/linux_misc.c
+++ sys/compat/linux/linux_misc.c
@@ -1055,6 +1055,7 @@
 int
 linux_wait4(struct thread *td, struct linux_wait4_args *args)
 {
+	struct proc *p;
 	int options, id, idtype;
 
 	if (args->options & ~(LINUX_WUNTRACED | LINUX_WNOHANG |
@@ -1084,6 +1085,12 @@
 	} else if (args->pid < 0) {
 		idtype = P_PGID;
 		id = (id_t)-args->pid;
+	} else if (args->pid == 0) {
+		idtype = P_PGID;
+		p = td->td_proc;
+		PROC_LOCK(p);
+		id = p->p_pgrp->pg_id;
+		PROC_UNLOCK(p);
 	} else {
 		idtype = P_PID;
 		id = (id_t)args->pid;