diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8b200ac7c..bd8d11f31 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@
 * Add reference genome to call of `has_liftover` in `get_liftover_genome` [(#259)](https://github.com/broadinstitute/gnomad_methods/pull/259)
 * Added fix for MQ calculation in `_get_info_agg_expr`, switched `RAW_MQ` and `MQ_DP` in calculation [(#262)](https://github.com/broadinstitute/gnomad_methods/pull/262)
 * Fix for error in `default_lift_data` caused by missing `results` field in `new_locus` [(#270)](https://github.com/broadinstitute/gnomad_methods/pull/270)
+* Fix for incorrect `ref_allele_mismatch` error in `liftover_expr` when the original reference allele has more than one bp [(#273)](https://github.com/broadinstitute/gnomad_methods/pull/273)
 
 ## Version 0.4.0 - July 9th, 2020
 
diff --git a/gnomad/utils/liftover.py b/gnomad/utils/liftover.py
index f6646ae98..6aabbd0f3 100644
--- a/gnomad/utils/liftover.py
+++ b/gnomad/utils/liftover.py
@@ -98,7 +98,9 @@ def liftover_expr(
         original_locus=locus,
         original_alleles=alleles,
         locus_fail_liftover=hl.is_missing(lifted_over_locus),
-        ref_allele_mismatch=lifted_over_locus.result.sequence_context()
+        ref_allele_mismatch=lifted_over_locus.result.sequence_context(
+            after=hl.len(alleles[0]) - 1
+        )
         != lifted_over_alleles[0],
     )