diff --git a/test/test_013_util.py b/test/test_013_util.py
index 32a5c5f..6c316bc 100644
--- a/test/test_013_util.py
+++ b/test/test_013_util.py
@@ -1,4 +1,4 @@
-from assembler.util import can_be_mark, can_convert_to_int, autoint
+from assembler.util import can_be_mark, can_convert_to_int, autoint, int16_2_bytes
 
 
 def test_can_be_mark():
@@ -33,3 +33,8 @@ def test_autoint():
 	assert autoint("0b1010101") == 0b1010101
 	assert autoint("'a'") == ord("a")
 	assert autoint("'\\n'") == ord("\n")
+
+def test_int16_2_bytes():
+	assert int16_2_bytes(2) == b"\x02\00"
+	assert int16_2_bytes(0x0200) == b"\x00\x02"
+	assert int16_2_bytes(-1) == b"\xff\xff"