diff --git a/hail/python/hail/vds/methods.py b/hail/python/hail/vds/methods.py
index 1bc532e2a80..ac8a7eb9615 100644
--- a/hail/python/hail/vds/methods.py
+++ b/hail/python/hail/vds/methods.py
@@ -983,7 +983,7 @@ def truncate_reference_blocks(ds, *, max_ref_block_base_pairs=None, ref_block_wi
 
     # we've changed LEN so we need to make sure that END is correct.
     if 'END' in new_rd.entry:
-        new_rd = VariantDataset._add_end(new_rd.drop('END'))
+        new_rd = new_rd.annotate_entries(END=new_rd.LEN + new_rd.locus.position - 1)
 
     if isinstance(ds, hl.vds.VariantDataset):
         return VariantDataset(reference_data=new_rd, variant_data=ds.variant_data)
diff --git a/hail/python/test/hail/vds/test_vds.py b/hail/python/test/hail/vds/test_vds.py
index 3879808e414..d785f855d74 100644
--- a/hail/python/test/hail/vds/test_vds.py
+++ b/hail/python/test/hail/vds/test_vds.py
@@ -895,11 +895,12 @@ def test_ref_block_does_not_densify_to_next_contig():
     ref = vds.reference_data
     var = vds.variant_data.filter_entries(False)
     # max out all chr1 refblocks, and truncate all chr2 refblocks so that nothing in chr2 should be densified
+    chr1_end = hl.parse_locus_interval('chr1', reference_genome=ref.locus.dtype.reference_genome).end.position
     ref = ref.annotate_entries(
-        END=hl.if_else(
+        LEN=hl.if_else(
             ref.locus.contig == 'chr1',
-            hl.parse_locus_interval('chr1', reference_genome=ref.locus.dtype.reference_genome).end.position,
-            ref.locus.position,
+            chr1_end - ref.locus.position + 1,
+            1,
         )
     )
     vds = hl.vds.VariantDataset(reference_data=ref, variant_data=var)