diff --git a/trezorlib/client.py b/trezorlib/client.py
index d54436e395..78e2452fac 100644
--- a/trezorlib/client.py
+++ b/trezorlib/client.py
@@ -90,7 +90,8 @@ def pprint(msg):
         return "<%s> (%d bytes):\n%s" % (msg_class, msg_size, msg)
 
 def log(msg):
-    sys.stderr.write(b'%s\n' % msg)
+    sys.stderr.write(msg)
+    sys.stderr.write('\n')
     sys.stderr.flush()
 
 class CallException(Exception):
diff --git a/trezorlib/protobuf_json.py b/trezorlib/protobuf_json.py
index 013d7a30b4..7d2b1be0f9 100644
--- a/trezorlib/protobuf_json.py
+++ b/trezorlib/protobuf_json.py
@@ -113,13 +113,13 @@ def pb2json(pb, useFieldNumber=False):
 _ftype2js = {
     FD.TYPE_DOUBLE: float,
     FD.TYPE_FLOAT: float,
-    FD.TYPE_INT64: long,
-    FD.TYPE_UINT64: long,
+    FD.TYPE_INT64: int,
+    FD.TYPE_UINT64: int,
     FD.TYPE_INT32: int,
     FD.TYPE_FIXED64: float,
     FD.TYPE_FIXED32: float,
     FD.TYPE_BOOL: bool,
-    FD.TYPE_STRING: unicode,
+    FD.TYPE_STRING: str,
     #FD.TYPE_MESSAGE: pb2json,              #handled specially
     FD.TYPE_BYTES: lambda x: x.encode('string_escape'),
     FD.TYPE_UINT32: int,
@@ -127,19 +127,19 @@ _ftype2js = {
     FD.TYPE_SFIXED32: float,
     FD.TYPE_SFIXED64: float,
     FD.TYPE_SINT32: int,
-    FD.TYPE_SINT64: long,
+    FD.TYPE_SINT64: int,
 }
 
 _js2ftype = {
     FD.TYPE_DOUBLE: float,
     FD.TYPE_FLOAT: float,
-    FD.TYPE_INT64: long,
-    FD.TYPE_UINT64: long,
+    FD.TYPE_INT64: int,
+    FD.TYPE_UINT64: int,
     FD.TYPE_INT32: int,
     FD.TYPE_FIXED64: float,
     FD.TYPE_FIXED32: float,
     FD.TYPE_BOOL: bool,
-    FD.TYPE_STRING: unicode,
+    FD.TYPE_STRING: str,
     # FD.TYPE_MESSAGE: json2pb,     #handled specially
     FD.TYPE_BYTES: lambda x: x.decode('string_escape'),
     FD.TYPE_UINT32: int,
@@ -147,7 +147,7 @@ _js2ftype = {
     FD.TYPE_SFIXED32: float,
     FD.TYPE_SFIXED64: float,
     FD.TYPE_SINT32: int,
-    FD.TYPE_SINT64: long,
+    FD.TYPE_SINT64: int,
 }
 
 # more monkey patching