diff --git a/contrib/pageinspect/heapfuncs.c b/contrib/pageinspect/heapfuncs.c
index f8ac343cc1..76d2cd1d27 100644
--- a/contrib/pageinspect/heapfuncs.c
+++ b/contrib/pageinspect/heapfuncs.c
@@ -232,7 +232,7 @@ heap_page_items(PG_FUNCTION_ARGS)
 					int			bits_len;
 
 					bits_len =
-						((tuphdr->t_infomask2 & HEAP_NATTS_MASK) / 8 + 1) * 8;
+						BITMAPLEN(HeapTupleHeaderGetNatts(tuphdr)) * BITS_PER_BYTE;
 					values[11] = CStringGetTextDatum(
 									 bits_to_text(tuphdr->t_bits, bits_len));
 				}
@@ -434,24 +434,19 @@ tuple_data_split(PG_FUNCTION_ARGS)
 		int			bits_str_len;
 		int			bits_len;
 
-		bits_len = (t_infomask2 & HEAP_NATTS_MASK) / 8 + 1;
+		bits_len = BITMAPLEN(t_infomask2 & HEAP_NATTS_MASK) * BITS_PER_BYTE;
 		if (!t_bits_str)
 			ereport(ERROR,
 					(errcode(ERRCODE_DATA_CORRUPTED),
 					 errmsg("argument of t_bits is null, but it is expected to be null and %d character long",
-							bits_len * 8)));
+							bits_len)));
 
 		bits_str_len = strlen(t_bits_str);
-		if ((bits_str_len % 8) != 0)
-			ereport(ERROR,
-					(errcode(ERRCODE_DATA_CORRUPTED),
-					 errmsg("length of t_bits is not a multiple of eight")));
-
-		if (bits_len * 8 != bits_str_len)
+		if (bits_len != bits_str_len)
 			ereport(ERROR,
 					(errcode(ERRCODE_DATA_CORRUPTED),
 					 errmsg("unexpected length of t_bits %u, expected %d",
-							bits_str_len, bits_len * 8)));
+							bits_str_len, bits_len)));
 
 		/* do the conversion */
 		t_bits = text_to_bits(t_bits_str, bits_str_len);