diff --git a/usr.sbin/jail/jail.c b/usr.sbin/jail/jail.c
index 920e573b914..eaef6d00424 100644
--- a/usr.sbin/jail/jail.c
+++ b/usr.sbin/jail/jail.c
@@ -31,6 +31,7 @@
 __FBSDID("$FreeBSD$");
 
 #include <sys/types.h>
+#include <sys/cpuset.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <sys/sysctl.h>
@@ -131,6 +132,16 @@ static const enum intparam stopcommands[] = {
     IP__NULL
 };
 
+static void
+reset_cpuset(void)
+{
+	cpusetid_t setid;
+
+	if (cpuset_getid(CPU_LEVEL_ROOT, CPU_WHICH_TID, -1, &setid) != 0)
+		return;
+	(void)cpuset_setid(CPU_WHICH_PID, -1, setid);
+}
+
 int
 main(int argc, char **argv)
 {
@@ -363,6 +374,9 @@ main(int argc, char **argv)
 			exit(1);
 	}
 
+	if ((op & (JF_START | JF_STOP)) != 0)
+		reset_cpuset();
+
 	jfp = NULL;
 	if (JidFile != NULL) {
 		jfp = fopen(JidFile, "w");