diff --git a/module/zfs/metaslab.c b/module/zfs/metaslab.c
index 5d89c65e6..d738eda60 100644
--- a/module/zfs/metaslab.c
+++ b/module/zfs/metaslab.c
@@ -5406,12 +5406,13 @@ metaslab_free_concrete(vdev_t *vd, uint64_t offset, uint64_t asize,
 {
 	metaslab_t *msp;
 	spa_t *spa = vd->vdev_spa;
+	int m = offset >> vd->vdev_ms_shift;
 
 	ASSERT(vdev_is_concrete(vd));
 	ASSERT3U(spa_config_held(spa, SCL_ALL, RW_READER), !=, 0);
-	ASSERT3U(offset >> vd->vdev_ms_shift, <, vd->vdev_ms_count);
+	VERIFY3U(m, <, vd->vdev_ms_count);
 
-	msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
+	msp = vd->vdev_ms[m];
 
 	VERIFY(!msp->ms_condensing);
 	VERIFY3U(offset, >=, msp->ms_start);