diff --git a/simplefix/__init__.py b/simplefix/__init__.py
index 556aef5..096aebf 100644
--- a/simplefix/__init__.py
+++ b/simplefix/__init__.py
@@ -27,6 +27,7 @@
 
 from .message import FixMessage, SOH
 from .parser import FixParser
+from .constants import *
 
 
 def pretty_print(s):
diff --git a/simplefix/constants.py b/simplefix/constants.py
new file mode 100644
index 0000000..c42c778
--- /dev/null
+++ b/simplefix/constants.py
@@ -0,0 +1,123 @@
+#! /usr/bin/env python
+########################################################################
+# SimpleFIX
+# Copyright (C) 2017, David Arnold.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+########################################################################
+
+"""FIX protocol constants."""
+
+SOH_BYTE = b'\x01'
+EQUALS_BYTE = b'='
+
+MSGTYPE_HEARTBEAT = b'0'
+MSGTYPE_TEST_REQUEST = b'1'
+MSGTYPE_RESEND_REQUEST = b'2'
+MSGTYPE_REJECT = b'3'
+MSGTYPE_SEQUENCE_RESET = b'4'
+MSGTYPE_LOGOUT = b'5'
+MSGTYPE_INDICATION_OF_INTEREST = b'6'
+MSGTYPE_ADVERTISEMENT = b'7'
+MSGTYPE_EXECUTION_REPORT = b'8'
+MSGTYPE_ORDER_CANCEL_REJECT = b'9'
+MSGTYPE_LOGON = b'A'
+MSGTYPE_NEWS = b'B'
+MSGTYPE_EMAIL = b'C'
+MSGTYPE_NEW_ORDER_SINGLE = b'D'
+MSGTYPE_NEW_ORDER_LIST = b'E'
+MSGTYPE_ORDER_CANCEL_REQUEST = b'F'
+MSGTYPE_ORDER_STATUS_REQUEST = b'G'
+MSGTYPE_ALLOCATION = b'J'
+MSGTYPE_LIST_CANCEL_REQUEST = b'K'
+MSGTYPE_LIST_EXECUTE = b'L'
+MSGTYPE_LIST_STATUS_REQUEST = b'M'
+MSGTYPE_LIST_STATUS = b'N'
+MSGTYPE_ALLOCATION_ACK = b'P'
+MSGTYPE_DONT_KNOW_TRADE = b'Q'
+MSGTYPE_QUOTE_REQUEST = b'R'
+MSGTYPE_QUOTE = b'S'
+MSGTYPE_SETTLEMENT_INSTRUCTIONS = b'T'
+MSGTYPE_MARKET_DATA_REQUEST = b'V'
+MSGTYPE_MARKET_DATA_SNAPSHOT_FULL_REFRESH = b'W'
+MSGTYPE_MARKET_DATA_INCREMENTAL_REFRESH = b'X'
+MSGTYPE_MARKET_DATA_REQUEST_REJECT = b'Y'
+MSGTYPE_QUOTE_CANCEL = b'Z'
+MSGTYPE_QUOTE_STATUS_REQUEST = b'a'
+MSGTYPE_QUOTE_ACKNOWLEDGEMENT = b'b'
+MSGYYPE_SECURITY_DEFINITION_REQUEST = b'c'
+MSGTYPE_SECURITY_DEFINITION = b'd'
+MSGTYPE_SECURITY_STATUS_REQUEST = b'e'
+MSGTYPE_SECURITY_STATUS = b'f'
+MSGTYPE_TRADING_SESSION_STATUS_REQUEST = b'g'
+MSGTYPE_TRADING_SESSION_STATUS = b'h'
+MSGTYPE_MASS_QUOTE = b'i'
+MSGTYPE_BUSINESS_MESSAGE_REJECT = b'j'
+MSGTYPE_BID_REQUEST = b'k'
+MSGTYPE_BID_RESPONSE = b'l'
+MSGTYPE_LIST_STRIKE_PRICE = b'm'
+MSGTYPE_XML_MESSAGE = b'n'
+MSGTYPE_REGISTRATION_INSTRUCTIONS = b'o'
+MSGTYPE_REGISTRATION_INSTRUCTIONS_RESPONSE = b'p'
+MSGTYPE_ORDER_MASS_CANCEL_REQUEST = b'q'
+MSGTYPE_ORDER_MASS_CANCEL_REPORT = b'r'
+MSGTYPE_NEW_ORDER_CROSS = b's'
+MSGTYPE_CROSS_ORDER_CANCEL_REPLACE_REQUEST = b't'
+MSGTYPE_CROSS_ORDER_CANCEL_REQUEST = b'u'
+MSGTYPE_SECURITY_TYPE_REQUEST = b'v'
+MSGTYPE_SECURITY_TYPES = b'w'
+MSGTYPE_SECURITY_LIST_REQUEST = b'x'
+MSGTYPE_SECURITY_LIST = b'y'
+MSGTYPE_DERIVATIVE_SECURITY_LIST_REQUEST = b'z'
+MSGTYPE_DERIVATIVE_SECURITY_LIST = b'AA'
+MSGTYPE_NEW_ORDER_MULTILEG = b'AB'
+MSGTYPE_MULTILEG_ORDER_CANCEL_REPLACE_REQUEST = b'AC'
+MSGTYPE_TRADE_CAPTURE_REPORT_REQUEST = b'AD'
+MSGTYPE_TRADE_CAPTURE_REPORT = b'AE'
+MSGTYPE_ORDER_MASS_STATUS_REQUEST = b'AF'
+MSGTYPE_QUOTE_REQUEST_REJECT = b'AG'
+MSGTYPE_RFQ_REQUEST = b'AH'
+MSGTYPE_QUOTE_STATUS_REPORT = b'AI'
+MSGTYPE_QUOTE_RESPONSE = b'AJ'
+MSGTYPE_CONFIRMATION = b'AK'
+MSGTYPE_POSITION_MAINTENANCE_REQUEST = b'AL'
+MSGTYPE_POSITION_MAINTENANCE_REPORT = b'AM'
+MSGTYPE_REQUEST_FOR_POSITIONS = b'AN'
+MSGTYPE_REQUEST_FOR_POSITIONS_ACK = b'AO'
+MSGTYPE_POSITION_REPORT = b'AP'
+MSGTYPE_TRADE_CAPTURE_REPORT_REQUEST_ACK = b'AQ'
+MSGTYPE_TRADE_CAPTURE_REPORT_ACK = b'AR'
+MSGTYPE_ALLOCATION_REPORT = b'AS'
+MSGTYPE_ALLOCATION_REPORT_ACK = b'AT'
+MSGTYPE_CONFIRMATION_ACK = b'AU'
+MSGTYPE_SETTLEMENT_INSTRUCTION_REQUEST = b'AV'
+MSGTYPE_ASSIGNMENT_REPORT = b'AW'
+MSGTYPE_COLLATERAL_REQUEST = b'AX'
+MSGTYPE_COLLATERAL_ASSIGNMENT = b'AY'
+MSGTYPE_COLLATERAL_RESPONSE = b'AZ'
+MSGTYPE_COLLATERAL_REPORT = b'BA'
+MSGTYPE_COLLATERAL_INQUIRY = b'BB'
+MSGTYPE_NETWORK_STATUS_REQUEST = b'BC'
+MSGTYPE_NETWORK_STATUS_RESPONSE = b'BD'
+MSGTYPE_USER_REQUEST = b'BE'
+MSGTYPE_USER_RESPONSE = b'BF'
+MSGTYPE_COLLATERAL_INQUIRY_ACK = b'BG'
+MSGTYPE_CONFIRMATION_REQUEST = 'BH'
+
diff --git a/test/all.py b/test/all.py
index e444d83..e7cb91e 100644
--- a/test/all.py
+++ b/test/all.py
@@ -25,9 +25,11 @@
 
 
 import unittest
+from test_constants import ConstantsTests
 from test_init import InitTests
 from test_message import MessageTests
 from test_parser import ParserTests
 
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/test/test_constants.py b/test/test_constants.py
new file mode 100644
index 0000000..07269b9
--- /dev/null
+++ b/test/test_constants.py
@@ -0,0 +1,44 @@
+#! /usr/bin/env python
+########################################################################
+# SimpleFIX
+# Copyright (C) 2017, David Arnold.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+########################################################################
+
+import unittest
+import simplefix
+
+
+class ConstantsTests(unittest.TestCase):
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def test_35(self):
+        self.assertEqual(b'0', simplefix.MSGTYPE_HEARTBEAT)
+        return
+
+
+if __name__ == "__main__":
+    unittest.main()