diff --git a/test/expected/functions.out b/test/expected/functions.out
index 84da2d8..0a1b1c4 100644
--- a/test/expected/functions.out
+++ b/test/expected/functions.out
@@ -158,32 +158,32 @@ SELECT l1_distance('[3e38]', '[-3e38]');
     Infinity
 (1 row)
 
-SELECT hamming_distance('\xFF', '\xFF');
+SELECT hamming_distance('\xFFFF', '\xFFFF');
  hamming_distance 
 ------------------
                 0
 (1 row)
 
-SELECT hamming_distance('\xFF', '\xFE');
+SELECT hamming_distance('\xFFFF', '\xFFFE');
  hamming_distance 
 ------------------
                 1
 (1 row)
 
-SELECT hamming_distance('\xFF', '\xFC');
+SELECT hamming_distance('\xFFFF', '\xFFFC');
  hamming_distance 
 ------------------
                 2
 (1 row)
 
-SELECT hamming_distance('\xFF', '\x00');
+SELECT hamming_distance('\xFFFF', '\x0000');
  hamming_distance 
 ------------------
-                8
+               16
 (1 row)
 
-SELECT hamming_distance('\xFF', '\x0000');
-ERROR:  different byte lengths 1 and 2
+SELECT hamming_distance('\xFFFF', '\x00');
+ERROR:  different byte lengths 2 and 1
 SELECT avg(v) FROM unnest(ARRAY['[1,2,3]'::vector, '[3,5,7]']) v;
     avg    
 -----------
diff --git a/test/sql/functions.sql b/test/sql/functions.sql
index fc657e2..95b2e15 100644
--- a/test/sql/functions.sql
+++ b/test/sql/functions.sql
@@ -37,11 +37,11 @@ SELECT l1_distance('[0,0]', '[0,1]');
 SELECT l1_distance('[1,2]', '[3]');
 SELECT l1_distance('[3e38]', '[-3e38]');
 
-SELECT hamming_distance('\xFF', '\xFF');
-SELECT hamming_distance('\xFF', '\xFE');
-SELECT hamming_distance('\xFF', '\xFC');
-SELECT hamming_distance('\xFF', '\x00');
-SELECT hamming_distance('\xFF', '\x0000');
+SELECT hamming_distance('\xFFFF', '\xFFFF');
+SELECT hamming_distance('\xFFFF', '\xFFFE');
+SELECT hamming_distance('\xFFFF', '\xFFFC');
+SELECT hamming_distance('\xFFFF', '\x0000');
+SELECT hamming_distance('\xFFFF', '\x00');
 
 SELECT avg(v) FROM unnest(ARRAY['[1,2,3]'::vector, '[3,5,7]']) v;
 SELECT avg(v) FROM unnest(ARRAY['[1,2,3]'::vector, '[3,5,7]', NULL]) v;