diff --git a/include/sys/range_tree.h b/include/sys/range_tree.h
index d80faa933e30..6e0025a2f147 100644
--- a/include/sys/range_tree.h
+++ b/include/sys/range_tree.h
@@ -126,11 +126,11 @@ rs_get_start_raw(const range_seg_t *rs, const range_tree_t *rt)
 	ASSERT3U(rt->rt_type, <=, RANGE_SEG_NUM_TYPES);
 	switch (rt->rt_type) {
 	case RANGE_SEG32:
-		return (((range_seg32_t *)rs)->rs_start);
+		return (((const range_seg32_t *)rs)->rs_start);
 	case RANGE_SEG64:
-		return (((range_seg64_t *)rs)->rs_start);
+		return (((const range_seg64_t *)rs)->rs_start);
 	case RANGE_SEG_GAP:
-		return (((range_seg_gap_t *)rs)->rs_start);
+		return (((const range_seg_gap_t *)rs)->rs_start);
 	default:
 		VERIFY(0);
 		return (0);
@@ -143,11 +143,11 @@ rs_get_end_raw(const range_seg_t *rs, const range_tree_t *rt)
 	ASSERT3U(rt->rt_type, <=, RANGE_SEG_NUM_TYPES);
 	switch (rt->rt_type) {
 	case RANGE_SEG32:
-		return (((range_seg32_t *)rs)->rs_end);
+		return (((const range_seg32_t *)rs)->rs_end);
 	case RANGE_SEG64:
-		return (((range_seg64_t *)rs)->rs_end);
+		return (((const range_seg64_t *)rs)->rs_end);
 	case RANGE_SEG_GAP:
-		return (((range_seg_gap_t *)rs)->rs_end);
+		return (((const range_seg_gap_t *)rs)->rs_end);
 	default:
 		VERIFY(0);
 		return (0);
diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c
index b848f7ef3033..1f143e42174b 100644
--- a/module/zfs/dsl_scan.c
+++ b/module/zfs/dsl_scan.c
@@ -1244,7 +1244,7 @@ dsl_scan_should_clear(dsl_scan_t *scn)
 		if (queue != NULL) {
 			/* # extents in exts_by_size = # in exts_by_addr */
 			mused += zfs_btree_numnodes(&queue->q_exts_by_size) *
-			    sizeof (range_seg_t) + queue->q_sio_memused;
+			    sizeof (range_seg_gap_t) + queue->q_sio_memused;
 		}
 		mutex_exit(&tvd->vdev_scan_io_queue_lock);
 	}