diff --git a/variation/validators/genomic_insertion.py b/variation/validators/genomic_insertion.py
index e84155a3..a887e1b4 100644
--- a/variation/validators/genomic_insertion.py
+++ b/variation/validators/genomic_insertion.py
@@ -49,7 +49,7 @@ async def get_valid_invalid_results(
             if ref:
                 # gnomAD VCF provides reference, so we should validate this
                 invalid_ref_msg = self.validate_reference_sequence(
-                    alt_ac, classification.pos0, classification.pos1 + len(ref) - 1, ref
+                    alt_ac, classification.pos0, classification.pos1, ref
                 )
                 if invalid_ref_msg:
                     errors.append(invalid_ref_msg)
diff --git a/variation/vrs_representation.py b/variation/vrs_representation.py
index 0df8b36f..8cfc4a4a 100644
--- a/variation/vrs_representation.py
+++ b/variation/vrs_representation.py
@@ -224,6 +224,7 @@ def to_vrs_allele(
                 state = alt or ""
 
             if alt_type == AltType.SUBSTITUTION:
+                # This accounts for MNVs
                 ival_end += len(state) - 1
 
             ival_start -= 1