diff --git a/tools/build_protobuf b/tools/build_protobuf
index abc4123330..4db3eeb190 100755
--- a/tools/build_protobuf
+++ b/tools/build_protobuf
@@ -1,12 +1,13 @@
 #!/bin/bash
 CURDIR=$(pwd)
 PB2DIR=$CURDIR/pb2
+OUTDIR=../trezorlib/messages
+INDEX=$OUTDIR/__init__.py
+
+mkdir -p $OUTDIR
 mkdir -p $PB2DIR
 touch $PB2DIR/__init__.py
 
-mkdir -p ../trezorlib/messages
-
-INDEX=../trezorlib/messages/__init__.py
 rm -f $INDEX
 echo '# Automatically generated by pb2py' >> $INDEX
 echo 'from __future__ import absolute_import' >> $INDEX
@@ -25,7 +26,7 @@ sed -i 's/^import types_pb2/from . import types_pb2/g' $CURDIR/pb2/storage_pb2.p
 for i in types messages storage ; do
     # Convert google protobuf library to trezor's internal format
     cd $CURDIR
-    ./pb2py -p $CURDIR -l $INDEX $i ../trezorlib/messages/
+    ./pb2py -p $CURDIR -l $INDEX $i $OUTDIR
 done
 
 rm -rf $PB2DIR
diff --git a/tools/pb2py b/tools/pb2py
index 0551cb2914..ef61d7e945 100755
--- a/tools/pb2py
+++ b/tools/pb2py
@@ -97,7 +97,7 @@ def process_type(t, cls, msg_id, indexfile, is_upy):
                 indexfile.write("%s = %d\n" % (t, msg_id))
 
     # Remove duplicate imports
-    imports = list(set(imports))
+    imports = sorted(list(set(imports)))
 
     if is_upy:
         imports = ['import protobuf as p'] + imports
@@ -105,7 +105,6 @@ def process_type(t, cls, msg_id, indexfile, is_upy):
         imports = ['from __future__ import absolute_import',
                    'from .. import protobuf as p'] + imports
 
-
     return imports + out
 
 
diff --git a/trezorlib/messages/NEMSignTx.py b/trezorlib/messages/NEMSignTx.py
index 82fbf2085b..fac2293956 100644
--- a/trezorlib/messages/NEMSignTx.py
+++ b/trezorlib/messages/NEMSignTx.py
@@ -1,13 +1,13 @@
 # Automatically generated by pb2py
 from __future__ import absolute_import
 from .. import protobuf as p
-from .NEMMosaicSupplyChange import NEMMosaicSupplyChange
-from .NEMTransfer import NEMTransfer
-from .NEMMosaicCreation import NEMMosaicCreation
-from .NEMTransactionCommon import NEMTransactionCommon
 from .NEMAggregateModification import NEMAggregateModification
-from .NEMProvisionNamespace import NEMProvisionNamespace
 from .NEMImportanceTransfer import NEMImportanceTransfer
+from .NEMMosaicCreation import NEMMosaicCreation
+from .NEMMosaicSupplyChange import NEMMosaicSupplyChange
+from .NEMProvisionNamespace import NEMProvisionNamespace
+from .NEMTransactionCommon import NEMTransactionCommon
+from .NEMTransfer import NEMTransfer
 
 
 class NEMSignTx(p.MessageType):
diff --git a/trezorlib/messages/TransactionType.py b/trezorlib/messages/TransactionType.py
index 903808f240..03ae17984a 100644
--- a/trezorlib/messages/TransactionType.py
+++ b/trezorlib/messages/TransactionType.py
@@ -1,8 +1,8 @@
 # Automatically generated by pb2py
 from __future__ import absolute_import
 from .. import protobuf as p
-from .TxOutputBinType import TxOutputBinType
 from .TxInputType import TxInputType
+from .TxOutputBinType import TxOutputBinType
 from .TxOutputType import TxOutputType
 
 
diff --git a/trezorlib/messages/TxRequest.py b/trezorlib/messages/TxRequest.py
index a0a934e856..0b1028b193 100644
--- a/trezorlib/messages/TxRequest.py
+++ b/trezorlib/messages/TxRequest.py
@@ -1,8 +1,8 @@
 # Automatically generated by pb2py
 from __future__ import absolute_import
 from .. import protobuf as p
-from .TxRequestSerializedType import TxRequestSerializedType
 from .TxRequestDetailsType import TxRequestDetailsType
+from .TxRequestSerializedType import TxRequestSerializedType
 
 
 class TxRequest(p.MessageType):