diff --git a/sys/cam/cam_sim.h b/sys/cam/cam_sim.h
--- a/sys/cam/cam_sim.h
+++ b/sys/cam/cam_sim.h
@@ -103,7 +103,6 @@
 	int			max_dev_openings;
 	u_int32_t		flags;
 #define	CAM_SIM_REL_TIMEOUT_PENDING	0x01
-#define	CAM_SIM_MPSAFE			0x02
 	struct callout		callout;
 	struct cam_devq 	*devq;	/* Device Queue to use for this SIM */
 	int			refcount; /* References to the SIM. */
diff --git a/sys/cam/cam_sim.c b/sys/cam/cam_sim.c
--- a/sys/cam/cam_sim.c
+++ b/sys/cam/cam_sim.c
@@ -72,9 +72,7 @@
 {
 	struct cam_sim *sim;
 
-	sim = (struct cam_sim *)malloc(sizeof(struct cam_sim),
-	    M_CAMSIM, M_ZERO | M_NOWAIT);
-
+	sim = malloc(sizeof(struct cam_sim), M_CAMSIM, M_ZERO | M_NOWAIT);
 	if (sim == NULL)
 		return (NULL);
 
@@ -92,13 +90,7 @@
 	sim->refcount = 1;
 	sim->devq = queue;
 	sim->mtx = mtx;
-	if (mtx == &Giant) {
-		sim->flags |= 0;
-		callout_init(&sim->callout, 0);
-	} else {
-		sim->flags |= CAM_SIM_MPSAFE;
-		callout_init(&sim->callout, 1);
-	}
+	callout_init(&sim->callout, 1);
 	return (sim);
 }