diff --git a/trezorlib/mapping.py b/trezorlib/mapping.py
index af4e03d..6221c61 100644
--- a/trezorlib/mapping.py
+++ b/trezorlib/mapping.py
@@ -1,46 +1,16 @@
 import trezor_pb2 as proto
 
-map_type_to_class = {
-    0: proto.Initialize,
-    1: proto.Ping,
-    2: proto.Success,
-    3: proto.Failure,
-    #4: proto.GetUID,
-    #5: proto.UUID,
-    9: proto.GetEntropy,
-    10: proto.Entropy,
-    11: proto.GetMasterPublicKey,
-    12: proto.MasterPublicKey,
-    13: proto.LoadDevice,
-    14: proto.ResetDevice,
-    15: proto.SignTx,
-    16: proto.SimpleSignTx,
-    17: proto.Features,
-    18: proto.PinMatrixRequest,
-    19: proto.PinMatrixAck,
-    20: proto.PinMatrixCancel,
-    21: proto.TxRequest,
-    # 22: proto.OutputRequest,
-    23: proto.TxInput,
-    24: proto.TxOutput,
-    25: proto.ApplySettings,
-    26: proto.ButtonRequest,
-    27: proto.ButtonAck,
-    28: proto.ButtonCancel,
-    29: proto.GetAddress,
-    30: proto.Address,
-    31: proto.SettingsType,
-    32: proto.XprvType,
-    33: proto.CoinType,
-    100: proto.DebugLinkDecision,
-    101: proto.DebugLinkGetState,
-    102: proto.DebugLinkState,
-    103: proto.DebugLinkStop,
-}
-
+map_type_to_class = {}
 map_class_to_type = {}
 
+def build_map():
+    for msg_type, i in proto.MessageType.items():
+        msg_name = msg_type.replace('MessageType_', '')
+        msg_class = getattr(proto, msg_name)
 
+        map_type_to_class[i] = msg_class
+        map_class_to_type[msg_class] = i
+    
 def get_type(msg):
     return map_class_to_type[msg.__class__]
 
@@ -48,23 +18,16 @@ def get_type(msg):
 def get_class(t):
     return map_type_to_class[t]
 
-
-def build_index():
-    for k, v in map_type_to_class.items():
-        map_class_to_type[v] = k
-
-
 def check_missing():
     from google.protobuf import reflection
 
-    types = [proto.__dict__[item] for item in dir(proto)
-             if issubclass(proto.__dict__[item].__class__, reflection.GeneratedProtocolMessageType)]
+    types = [getattr(proto, item) for item in dir(proto)
+             if issubclass(getattr(proto, item).__class__, reflection.GeneratedProtocolMessageType)]
 
     missing = list(set(types) - set(map_type_to_class.values()))
 
     if len(missing):
         raise Exception("Following protobuf messages are not defined in mapping: %s" % missing)
 
-
+build_map()
 check_missing()
-build_index()