diff --git a/sys/kern/subr_epoch.c b/sys/kern/subr_epoch.c
--- a/sys/kern/subr_epoch.c
+++ b/sys/kern/subr_epoch.c
@@ -468,9 +468,7 @@
 
 	MPASS(cold || epoch != NULL);
 	td = curthread;
-	MPASS((vm_offset_t)et >= td->td_kstack &&
-	    (vm_offset_t)et + sizeof(struct epoch_tracker) <=
-	    td->td_kstack + td->td_kstack_pages * PAGE_SIZE);
+	MPASS(kstack_contains(td, (vm_offset_t)et, sizeof(*et)));
 
 	INIT_CHECK(epoch);
 	MPASS(epoch->e_flags & EPOCH_PREEMPT);