diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index d147b8e910..7e4f307351 100644
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -3928,7 +3928,7 @@ spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
 	 * saves us a pre-read to get data we don't actually care about.
 	 */
 	bufsize = P2ROUNDUP(nvsize, SPA_CONFIG_BLOCKSIZE);
-	packed = kmem_alloc(bufsize, KM_SLEEP);
+	packed = vmem_alloc(bufsize, KM_SLEEP);
 
 	VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
 	    KM_SLEEP) == 0);
@@ -3936,7 +3936,7 @@ spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
 
 	dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
 
-	kmem_free(packed, bufsize);
+	vmem_free(packed, bufsize);
 
 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
 	dmu_buf_will_dirty(db, tx);