diff --git a/sys/dev/dc/if_dc.c b/sys/dev/dc/if_dc.c
index 7013a6c38628..dc938fa9c640 100644
--- a/sys/dev/dc/if_dc.c
+++ b/sys/dev/dc/if_dc.c
@@ -2289,7 +2289,7 @@ dc_attach(device_t dev)
 	ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);
 	ifp->if_capabilities |= IFCAP_VLAN_MTU;
 
-	callout_init(&sc->dc_stat_ch, IS_MPSAFE);
+	callout_init(&sc->dc_stat_ch, IS_MPSAFE ? CALLOUT_MPSAFE : 0);
 
 #ifdef SRM_MEDIA
 	sc->dc_srm_media = 0;
diff --git a/sys/dev/hifn/hifn7751.c b/sys/dev/hifn/hifn7751.c
index 4486845666d0..4f787c0b3b18 100644
--- a/sys/dev/hifn/hifn7751.c
+++ b/sys/dev/hifn/hifn7751.c
@@ -487,8 +487,7 @@ hifn_attach(device_t dev)
 	if (sc->sc_flags & (HIFN_HAS_PUBLIC | HIFN_HAS_RNG))
 		hifn_init_pubrng(sc);
 
-	/* NB: 1 means the callout runs w/o Giant locked */
-	callout_init(&sc->sc_tickto, 1);
+	callout_init(&sc->sc_tickto, CALLOUT_MPSAFE);
 	callout_reset(&sc->sc_tickto, hz, hifn_tick, sc);
 
 	return (0);
@@ -687,8 +686,7 @@ hifn_init_pubrng(struct hifn_softc *sc)
 			sc->sc_rnghz = hz / 100;
 		else
 			sc->sc_rnghz = 1;
-		/* NB: 1 means the callout runs w/o Giant locked */
-		callout_init(&sc->sc_rngto, 1);
+		callout_init(&sc->sc_rngto, CALLOUT_MPSAFE);
 		callout_reset(&sc->sc_rngto, sc->sc_rnghz, hifn_rng, sc);
 	}
 
diff --git a/sys/dev/patm/if_patm_attach.c b/sys/dev/patm/if_patm_attach.c
index 932bb6fb3e28..036bc41fff83 100644
--- a/sys/dev/patm/if_patm_attach.c
+++ b/sys/dev/patm/if_patm_attach.c
@@ -204,7 +204,7 @@ patm_attach(device_t dev)
 	mtx_init(&sc->tst_lock, "tst lock", NULL, MTX_DEF);
 	cv_init(&sc->vcc_cv, "vcc_close");
 
-	callout_init(&sc->tst_callout, 1);
+	callout_init(&sc->tst_callout, CALLOUT_MPSAFE);
 
 	sysctl_ctx_init(&sc->sysctl_ctx);
 
diff --git a/sys/dev/rndtest/rndtest.c b/sys/dev/rndtest/rndtest.c
index 15bbc0996e8e..523209511943 100644
--- a/sys/dev/rndtest/rndtest.c
+++ b/sys/dev/rndtest/rndtest.c
@@ -96,8 +96,7 @@ rndtest_attach(device_t dev)
 #if __FreeBSD_version < 500000
 		callout_init(&rsp->rs_to);
 #else
-		/* NB: 1 means the callout runs w/o Giant locked */
-		callout_init(&rsp->rs_to, 1);
+		callout_init(&rsp->rs_to, CALLOUT_MPSAFE);
 #endif
 	} else
 		device_printf(dev, "rndtest_init: no memory for state block\n");
diff --git a/sys/dev/safe/safe.c b/sys/dev/safe/safe.c
index 67f9233e60c4..ebd170e3fc6e 100644
--- a/sys/dev/safe/safe.c
+++ b/sys/dev/safe/safe.c
@@ -441,8 +441,7 @@ safe_attach(device_t dev)
 #endif
 		safe_rng_init(sc);
 
-		/* NB: 1 means the callout runs w/o Giant locked */
-		callout_init(&sc->sc_rngto, 1);
+		callout_init(&sc->sc_rngto, CALLOUT_MPSAFE);
 		callout_reset(&sc->sc_rngto, hz*safe_rnginterval, safe_rng, sc);
 	}
 #endif /* SAFE_NO_RNG */
diff --git a/sys/dev/ubsec/ubsec.c b/sys/dev/ubsec/ubsec.c
index c9382ba22eb3..eb594c90d997 100644
--- a/sys/dev/ubsec/ubsec.c
+++ b/sys/dev/ubsec/ubsec.c
@@ -462,8 +462,7 @@ ubsec_attach(device_t dev)
 			sc->sc_rnghz = hz / 100;
 		else
 			sc->sc_rnghz = 1;
-		/* NB: 1 means the callout runs w/o Giant locked */
-		callout_init(&sc->sc_rngto, 1);
+		callout_init(&sc->sc_rngto, CALLOUT_MPSAFE);
 		callout_reset(&sc->sc_rngto, sc->sc_rnghz, ubsec_rng, sc);
 skip_rng:
 	;
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index 9af07a9db39f..d006522266be 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -386,8 +386,8 @@ proc0_init(void *dummy __unused)
 
 	bcopy("swapper", p->p_comm, sizeof ("swapper"));
 
-	callout_init(&p->p_itcallout, 1);
-	callout_init(&td->td_slpcallout, 1);
+	callout_init(&p->p_itcallout, CALLOUT_MPSAFE);
+	callout_init(&td->td_slpcallout, CALLOUT_MPSAFE);
 
 	/* Create credentials. */
 	p->p_ucred = crget();
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 14f637790812..5330dcdf2942 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -592,7 +592,7 @@ fork1(td, flags, pages, procp)
 	PGRP_UNLOCK(p1->p_pgrp);
 	LIST_INIT(&p2->p_children);
 
-	callout_init(&p2->p_itcallout, 1);
+	callout_init(&p2->p_itcallout, CALLOUT_MPSAFE);
 
 #ifdef KTRACE
 	/*
diff --git a/sys/kern/kern_kse.c b/sys/kern/kern_kse.c
index 2f93b1e560e0..2af36c4dd668 100644
--- a/sys/kern/kern_kse.c
+++ b/sys/kern/kern_kse.c
@@ -1337,7 +1337,7 @@ thread_link(struct thread *td, struct ksegrp *kg)
 	td->td_kse      = NULL;
 
 	LIST_INIT(&td->td_contested);
-	callout_init(&td->td_slpcallout, 1);
+	callout_init(&td->td_slpcallout, CALLOUT_MPSAFE);
 	TAILQ_INSERT_HEAD(&p->p_threads, td, td_plist);
 	TAILQ_INSERT_HEAD(&kg->kg_threads, td, td_kglist);
 	p->p_numthreads++;
diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 9e6dcf5edbfa..2733d4228833 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -652,7 +652,7 @@ sched_setup(dummy)
 	void *dummy;
 {
 	callout_init(&loadav_callout, 0);
-	callout_init(&lbolt_callout, 1);
+	callout_init(&lbolt_callout, CALLOUT_MPSAFE);
 
 	/* Kick off timeout driven events by calling first time. */
 	loadav(NULL);
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c
index 2f93b1e560e0..2af36c4dd668 100644
--- a/sys/kern/kern_thread.c
+++ b/sys/kern/kern_thread.c
@@ -1337,7 +1337,7 @@ thread_link(struct thread *td, struct ksegrp *kg)
 	td->td_kse      = NULL;
 
 	LIST_INIT(&td->td_contested);
-	callout_init(&td->td_slpcallout, 1);
+	callout_init(&td->td_slpcallout, CALLOUT_MPSAFE);
 	TAILQ_INSERT_HEAD(&p->p_threads, td, td_plist);
 	TAILQ_INSERT_HEAD(&kg->kg_threads, td, td_kglist);
 	p->p_numthreads++;
diff --git a/sys/kern/sched_4bsd.c b/sys/kern/sched_4bsd.c
index 2561759e9e9e..67257bb7e02f 100644
--- a/sys/kern/sched_4bsd.c
+++ b/sys/kern/sched_4bsd.c
@@ -403,7 +403,7 @@ sched_setup(void *dummy)
 		sched_quantum = SCHED_QUANTUM;
 	hogticks = 2 * sched_quantum;
 
-	callout_init(&schedcpu_callout, 1);
+	callout_init(&schedcpu_callout, CALLOUT_MPSAFE);
 	callout_init(&roundrobin_callout, 0);
 
 	/* Kick off timeout driven events by calling first time. */
diff --git a/sys/kern/sched_ule.c b/sys/kern/sched_ule.c
index a24154c9d1be..b5b31ba2d330 100644
--- a/sys/kern/sched_ule.c
+++ b/sys/kern/sched_ule.c
@@ -569,7 +569,7 @@ sched_setup(void *dummy)
 			kseq_cpu[i].ksq_cpus = cg->cg_count;
 		}
 	}
-	callout_init(&kseq_lb_callout, 1);
+	callout_init(&kseq_lb_callout, CALLOUT_MPSAFE);
 	kseq_balance(NULL);
 #else
 	kseq_setup(KSEQ_SELF());
diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index ff8112cbc10e..23a35cc38c07 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -355,7 +355,7 @@ bpfopen(dev, flags, fmt, td)
 	mac_create_bpfdesc(td->td_ucred, d);
 #endif
 	mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF);
-	callout_init(&d->bd_callout, 1);
+	callout_init(&d->bd_callout, CALLOUT_MPSAFE);
 
 	return (0);
 }
diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c
index 1f0010195c79..031a7bccdbd7 100644
--- a/sys/netinet/tcp_syncache.c
+++ b/sys/netinet/tcp_syncache.c
@@ -269,7 +269,7 @@ syncache_init(void)
 	/* Initialize the timer queues. */
 	for (i = 0; i <= SYNCACHE_MAXREXMTS; i++) {
 		TAILQ_INIT(&tcp_syncache.timerq[i]);
-		callout_init(&tcp_syncache.tt_timerq[i], 1);
+		callout_init(&tcp_syncache.tt_timerq[i], CALLOUT_MPSAFE);
 	}
 
 	/*
diff --git a/sys/pci/if_dc.c b/sys/pci/if_dc.c
index 7013a6c38628..dc938fa9c640 100644
--- a/sys/pci/if_dc.c
+++ b/sys/pci/if_dc.c
@@ -2289,7 +2289,7 @@ dc_attach(device_t dev)
 	ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);
 	ifp->if_capabilities |= IFCAP_VLAN_MTU;
 
-	callout_init(&sc->dc_stat_ch, IS_MPSAFE);
+	callout_init(&sc->dc_stat_ch, IS_MPSAFE ? CALLOUT_MPSAFE : 0);
 
 #ifdef SRM_MEDIA
 	sc->dc_srm_media = 0;