diff --git a/src/backend/statistics/mcv.c b/src/backend/statistics/mcv.c
index 256728a..cfe7e54 100644
--- a/src/backend/statistics/mcv.c
+++ b/src/backend/statistics/mcv.c
@@ -40,13 +40,14 @@
  * stored in a separate array (deduplicated, to minimize the size), and
  * so the serialized items only store uint16 indexes into that array.
  *
- * Each serialized item store (in this order):
+ * Each serialized item stores (in this order):
  *
  * - indexes to values	  (ndim * sizeof(uint16))
  * - null flags			  (ndim * sizeof(bool))
  * - frequency			  (sizeof(double))
  * - base_frequency		  (sizeof(double))
  *
+ * There is no alignment padding within an MCV item.
  * So in total each MCV item requires this many bytes:
  *
  *	 ndim * (sizeof(uint16) + sizeof(bool)) + 2 * sizeof(double)
@@ -61,7 +62,7 @@
 	(VARHDRSZ + sizeof(uint32) * 3 + sizeof(AttrNumber))
 
 /*
- * Size of the serialized MCV list, exluding the space needed for
+ * Size of the serialized MCV list, excluding the space needed for
  * deduplicated per-dimension values. The macro is meant to be used
  * when it's not yet safe to access the serialized info about amount
  * of data for each column.
@@ -619,6 +620,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 		else if (info[dim].typlen == -1)	/* varlena */
 		{
 			info[dim].nbytes = 0;
+			info[dim].nbytes_aligned = 0;
 			for (i = 0; i < info[dim].nvalues; i++)
 			{
 				Size		len;
@@ -646,6 +648,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 		else if (info[dim].typlen == -2)	/* cstring */
 		{
 			info[dim].nbytes = 0;
+			info[dim].nbytes_aligned = 0;
 			for (i = 0; i < info[dim].nvalues; i++)
 			{
 				Size		len;
@@ -743,7 +746,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 				 * assumes little endian behavior.  store_att_byval does
 				 * almost what we need, but it requires properly aligned
 				 * buffer - the output buffer does not guarantee that. So we
-				 * simply use a static Datum variable (which guarantees proper
+				 * simply use a local Datum variable (which guarantees proper
 				 * alignment), and then copy the value from it.
 				 */
 				store_att_byval(&tmp, value, info[dim].typlen);
@@ -759,14 +762,14 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 			}
 			else if (info[dim].typlen == -1)	/* varlena */
 			{
-				uint32		len = VARSIZE_ANY_EXHDR(value);
+				uint32		len = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
 
 				/* copy the length */
 				memcpy(ptr, &len, sizeof(uint32));
 				ptr += sizeof(uint32);
 
 				/* data from the varlena value (without the header) */
-				memcpy(ptr, VARDATA(DatumGetPointer(value)), len);
+				memcpy(ptr, VARDATA_ANY(DatumGetPointer(value)), len);
 				ptr += len;
 			}
 			else if (info[dim].typlen == -2)	/* cstring */
@@ -1100,7 +1103,7 @@ statext_mcv_deserialize(bytea *data)
 					map[dim][i] = PointerGetDatum(dataptr);
 
 					/* skip to place of the next deserialized value */
-					dataptr += MAXALIGN(len);
+					dataptr += MAXALIGN(len + VARHDRSZ);
 				}
 			}
 			else if (info[dim].typlen == -2)
diff --git a/src/include/statistics/extended_stats_internal.h b/src/include/statistics/extended_stats_internal.h
index 6778746..8fc5419 100644
--- a/src/include/statistics/extended_stats_internal.h
+++ b/src/include/statistics/extended_stats_internal.h
@@ -36,7 +36,7 @@ typedef struct DimensionInfo
 {
 	int			nvalues;		/* number of deduplicated values */
 	int			nbytes;			/* number of bytes (serialized) */
-	int			nbytes_aligned;	/* deserialized data with alignment */
+	int			nbytes_aligned;	/* size of deserialized data with alignment */
 	int			typlen;			/* pg_type.typlen */
 	bool		typbyval;		/* pg_type.typbyval */
 } DimensionInfo;