diff --git a/test/unit_tests_d/ut_scrypt.py b/test/unit_tests_d/ut_scrypt.py
new file mode 100755
index 00000000..2944c73e
--- /dev/null
+++ b/test/unit_tests_d/ut_scrypt.py
@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+"""
+test/unit_tests_d/ut_scrypt.py: password hashing unit test for the MMGen suite
+"""
+
+from test.common import *
+
+class unit_test(object):
+
+	def run_test(self,name):
+		import time
+
+		msg_r('Testing password hashing...')
+		qmsg('')
+		from mmgen.crypto import scrypt_hash_passphrase
+
+		salt = bytes.fromhex('f00f' * 16)
+
+		presets = { '1': '64898d01ffcea1252c17411e7bd6c12d00191ee8ddcbf95420e5de8f37a7a1cb',
+					'2': '625d0c59fcbcf85eca51b4337d3a4952e554c7c95fe32f4199ad0e9e9370e279',
+					'3': 'b30a5cf0e606515be4a983cc4a1a4c21e04806f19aaa0ad354a353c83aecd3ee',
+					'4': 'a3a1b99393734510b68adf2c2cfdc627a2bc3281913d8ea6fbb677d39781a9fa',
+					'5': '0c7e1a672738cee49cf0ff6f3208190ca418e741835fd6995ce9558cc19f3f04',
+					'6': '91f9d1c9baf3948433dab58dcc912d96035392c1db21ede96d2f369e025ab06d',
+					'7': 'fcb2cd05268de43b0d2d45f78a56e5d446b0bd2d3b57bdbc77cc17a42942f1bd' }
+
+		pws = ( ('',      'cc8d99ce7365d8a9d2422d71ce330e130b2cade46a8cc0459a3f83e1a6ac3d30'),
+				('foo',   'f0e2cce1d9980edf2373a2070ad3560c2506faf9bc50704a1bc5cdb3c7f63f3b'),
+				('φυβαρ', '64898d01ffcea1252c17411e7bd6c12d00191ee8ddcbf95420e5de8f37a7a1cb') )
+
+		def test_passwords():
+			for pw_base,res in pws:
+				for pw in (pw_base,pw_base.encode()):
+					pw_disp = "'"+pw+"'" if type(pw) == str else "b'"+pw.decode()+"'"
+					if opt.quiet:
+						omsg_r('.')
+					else:
+						msg_r('  password {:9} '.format(pw_disp))
+					ret = scrypt_hash_passphrase(pw,salt,'1').hex()
+					assert ret == res, ret
+
+		def test_presets(do_presets):
+			vmsg('  id    N   p  r')
+			for hp in do_presets:
+				hp = str(hp)
+				res = presets[hp]
+				pw = 'φυβαρ'
+				if opt.quiet:
+					omsg_r('.')
+				else:
+					msg_r('  {!r:3}: {!r:12}  '.format(hp,g.hash_presets[hp]))
+				st = time.time()
+				ret = scrypt_hash_passphrase(pw,salt,hp).hex()
+				t = time.time() - st
+				vmsg('  {:0.4f} secs'.format(t))
+				assert ret == res, ret
+
+		if opt.quiet: silence()
+
+		g.force_standalone_scrypt_module = False
+		vmsg('Passwords:')
+		test_passwords()
+		vmsg('Hash presets:')
+		test_presets((1,2,3,4) if opt.fast else (1,2,3,4,5,6,7))
+
+		g.force_standalone_scrypt_module = True
+		vmsg('Passwords (standalone scrypt):')
+		test_passwords()
+		vmsg('Hash presets (standalone scrypt):')
+		test_presets((1,2,3))
+
+		if opt.quiet: end_silence()
+
+		msg('OK')
+		return True