diff --git a/CHANGELOG.md b/CHANGELOG.md
index aa817e7..3c82430 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [unreleased]
 
+- MODBUS: the last digit of the inverter version is a hexadecimal number [#119](https://github.com/s-allius/tsun-gen3-proxy/issues/119)
 - GEN3PLUS: add client_mode connection on port 8899 [#117](https://github.com/s-allius/tsun-gen3-proxy/issues/117)
 
 ## [0.9.0] - 2024-07-01
diff --git a/app/src/modbus.py b/app/src/modbus.py
index 2b3a335..63c2d19 100644
--- a/app/src/modbus.py
+++ b/app/src/modbus.py
@@ -44,7 +44,7 @@ class Modbus():
         0x203e: {'reg': Register.NO_INPUTS,   'fmt': '!H', 'ratio':  1/256},  # noqa: E501
 
         0x3000: {'reg': Register.INVERTER_STATUS,      'fmt': '!H'},                 # noqa: E501
-        0x3008: {'reg': Register.VERSION,              'fmt': '!H', 'eval': "f'V{(result>>12)}.{(result>>8)&0xf}.{(result>>4)&0xf}{result&0xf}'"},  # noqa: E501
+        0x3008: {'reg': Register.VERSION,              'fmt': '!H', 'eval': "f'V{(result>>12)}.{(result>>8)&0xf}.{(result>>4)&0xf}{result&0xf:1X}'"},  # noqa: E501
         0x3009: {'reg': Register.GRID_VOLTAGE,         'fmt': '!H', 'ratio':  0.1},  # noqa: E501
         0x300a: {'reg': Register.GRID_CURRENT,         'fmt': '!H', 'ratio': 0.01},  # noqa: E501
         0x300b: {'reg': Register.GRID_FREQUENCY,       'fmt': '!H', 'ratio': 0.01},  # noqa: E501
diff --git a/app/tests/test_modbus.py b/app/tests/test_modbus.py
index 0009182..16cb7ce 100644
--- a/app/tests/test_modbus.py
+++ b/app/tests/test_modbus.py
@@ -32,7 +32,12 @@ def test_modbus_crc():
     assert mb._Modbus__check_crc(b'\x01\x06\x20\x08\x00\x00\x03\xc8')
 
     assert 0x5c75 == mb._Modbus__calc_crc(b'\x01\x03\x08\x01\x2c\x00\x2c\x02\x2c\x2c\x46')
-    
+    msg = b'\x01\x03\x28\x51'
+    msg += b'\x0e\x08\xd3\x00\x29\x13\x87\x00\x3e\x00\x00\x01\x2c\x03\xb4\x00'
+    msg += b'\x08\x00\x00\x00\x00\x01\x59\x01\x21\x03\xe6\x00\x00\x00\x00\x00'
+    msg += b'\x00\x00\x00\x00\x00\x00\x00\xe6\xef'
+    assert 0 == mb._Modbus__calc_crc(msg)
+
 def test_build_modbus_pdu():
     '''Check building and sending a MODBUS RTU'''
     mb = ModbusTestHelper()
@@ -173,7 +178,7 @@ def test_parse_resp():
     assert mb.req_pend
 
     call = 0
-    exp_result = ['V0.0.212', 4.4, 0.7, 0.7, 30]
+    exp_result = ['V0.0.2C', 4.4, 0.7, 0.7, 30]
     for key, update, val in mb.recv_resp(mb.db, b'\x01\x03\x0c\x01\x2c\x00\x2c\x00\x2c\x00\x46\x00\x46\x00\x46\x32\xc8', 'test'):
         if key == 'grid':
             assert update == True
@@ -222,7 +227,7 @@ def test_queue2():
     assert mb.send_calls == 1
     assert mb.pdu == b'\x01\x030\x07\x00\x06{\t'
     call = 0
-    exp_result = ['V0.0.212', 4.4, 0.7, 0.7, 30]
+    exp_result = ['V0.0.2C', 4.4, 0.7, 0.7, 30]
     for key, update, val in mb.recv_resp(mb.db, b'\x01\x03\x0c\x01\x2c\x00\x2c\x00\x2c\x00\x46\x00\x46\x00\x46\x32\xc8', 'test'):
         if key == 'grid':
             assert update == True
@@ -272,7 +277,7 @@ def test_queue3():
     assert mb.recv_responses == 0
 
     call = 0
-    exp_result = ['V0.0.212', 4.4, 0.7, 0.7, 30]
+    exp_result = ['V0.0.2C', 4.4, 0.7, 0.7, 30]
     for key, update, val in mb.recv_resp(mb.db, b'\x01\x03\x0c\x01\x2c\x00\x2c\x00\x2c\x00\x46\x00\x46\x00\x46\x32\xc8', 'test'):
         if key == 'grid':
             assert update == True
diff --git a/app/tests/test_talent.py b/app/tests/test_talent.py
index f8efca0..5997cd8 100644
--- a/app/tests/test_talent.py
+++ b/app/tests/test_talent.py
@@ -339,6 +339,15 @@ def MsgModbusResp20():
     msg += b'\x00\x00\x00\x00\x00\x00\x00\xdb\x6b'
     return msg
 
+@pytest.fixture
+def MsgModbusResp21():
+    msg  = b'\x00\x00\x00\x45\x10R170000000000001'
+    msg += b'\x91\x77\x17\x18\x19\x1a\x2d\x01\x03\x28\x51'
+    msg += b'\x0e\x08\xd3\x00\x29\x13\x87\x00\x3e\x00\x00\x01\x2c\x03\xb4\x00'
+    msg += b'\x08\x00\x00\x00\x00\x01\x59\x01\x21\x03\xe6\x00\x00\x00\x00\x00'
+    msg += b'\x00\x00\x00\x00\x00\x00\x00\xe6\xef'
+    return msg
+
 def test_read_message(MsgContactInfo):
     m = MemoryStream(MsgContactInfo, (0,))
     m.read()         # read complete msg, and dispatch msg
@@ -1226,11 +1235,11 @@ def test_msg_modbus_rsp2(ConfigTsunInv1, MsgModbusResp20):
 
     m.close()
 
-def test_msg_modbus_rsp3(ConfigTsunInv1, MsgModbusResp20):
+def test_msg_modbus_rsp3(ConfigTsunInv1, MsgModbusResp21):
     '''Modbus response with a valid Modbus request must be forwarded'''
     ConfigTsunInv1
-    m = MemoryStream(MsgModbusResp20)
-    m.append_msg(MsgModbusResp20)
+    m = MemoryStream(MsgModbusResp21)
+    m.append_msg(MsgModbusResp21)
 
     m.mb.rsp_handler = m.msg_forward
     m.mb.last_addr = 1
@@ -1247,10 +1256,10 @@ def test_msg_modbus_rsp3(ConfigTsunInv1, MsgModbusResp20):
     assert not m.header_valid  # must be invalid, since msg was handled and buffer flushed
     assert m.mb.err == 0
     assert m.msg_count == 1
-    assert m._forward_buffer==MsgModbusResp20
+    assert m._forward_buffer==MsgModbusResp21
     assert m._send_buffer==b''
-    assert m.db.db == {'inverter': {'Version': 'V5.1.09', 'Rated_Power': 300}, 'grid': {'Voltage': 225.9, 'Current': 0.41, 'Frequency': 49.99, 'Output_Power': 94.8}, 'env': {'Inverter_Temp': 22}, 'input': {'pv1': {'Voltage': 0.8, 'Current': 0.0, 'Power': 0.0}, 'pv2': {'Voltage': 34.5, 'Current': 2.89, 'Power': 99.8}, 'pv3': {'Voltage': 0.0, 'Current': 0.0, 'Power': 0.0}, 'pv4': {'Voltage': 0.0, 'Current': 0.0, 'Power': 0.0}}}
-    assert m.db.get_db_value(Register.VERSION) == 'V5.1.09'
+    assert m.db.db == {'inverter': {'Version': 'V5.1.0E', 'Rated_Power': 300}, 'grid': {'Voltage': 225.9, 'Current': 0.41, 'Frequency': 49.99, 'Output_Power': 94.8}, 'env': {'Inverter_Temp': 22}, 'input': {'pv1': {'Voltage': 0.8, 'Current': 0.0, 'Power': 0.0}, 'pv2': {'Voltage': 34.5, 'Current': 2.89, 'Power': 99.8}, 'pv3': {'Voltage': 0.0, 'Current': 0.0, 'Power': 0.0}, 'pv4': {'Voltage': 0.0, 'Current': 0.0, 'Power': 0.0}}}
+    assert m.db.get_db_value(Register.VERSION) == 'V5.1.0E'
     assert m.new_data['inverter'] == True
     m.new_data['inverter'] = False
     assert m.mb.req_pend == False
@@ -1259,10 +1268,10 @@ def test_msg_modbus_rsp3(ConfigTsunInv1, MsgModbusResp20):
     assert not m.header_valid  # must be invalid, since msg was handled and buffer flushed
     assert m.mb.err == 5
     assert m.msg_count == 2
-    assert m._forward_buffer==MsgModbusResp20
+    assert m._forward_buffer==MsgModbusResp21
     assert m._send_buffer==b''
-    assert m.db.db == {'inverter': {'Version': 'V5.1.09', 'Rated_Power': 300}, 'grid': {'Voltage': 225.9, 'Current': 0.41, 'Frequency': 49.99, 'Output_Power': 94.8}, 'env': {'Inverter_Temp': 22}, 'input': {'pv1': {'Voltage': 0.8, 'Current': 0.0, 'Power': 0.0}, 'pv2': {'Voltage': 34.5, 'Current': 2.89, 'Power': 99.8}, 'pv3': {'Voltage': 0.0, 'Current': 0.0, 'Power': 0.0}, 'pv4': {'Voltage': 0.0, 'Current': 0.0, 'Power': 0.0}}}
-    assert m.db.get_db_value(Register.VERSION) == 'V5.1.09'
+    assert m.db.db == {'inverter': {'Version': 'V5.1.0E', 'Rated_Power': 300}, 'grid': {'Voltage': 225.9, 'Current': 0.41, 'Frequency': 49.99, 'Output_Power': 94.8}, 'env': {'Inverter_Temp': 22}, 'input': {'pv1': {'Voltage': 0.8, 'Current': 0.0, 'Power': 0.0}, 'pv2': {'Voltage': 34.5, 'Current': 2.89, 'Power': 99.8}, 'pv3': {'Voltage': 0.0, 'Current': 0.0, 'Power': 0.0}, 'pv4': {'Voltage': 0.0, 'Current': 0.0, 'Power': 0.0}}}
+    assert m.db.get_db_value(Register.VERSION) == 'V5.1.0E'
     assert m.new_data['inverter'] == False
 
     m.close()