diff --git a/clearml/binding/artifacts.py b/clearml/binding/artifacts.py
index 5e773bbc..0c2c6872 100644
--- a/clearml/binding/artifacts.py
+++ b/clearml/binding/artifacts.py
@@ -141,7 +141,7 @@ class Artifact(object):
         self._object = self._not_set
 
     def get(self, force_download=False, deserialization_function=None):
-        # type: (bool, Optional[Callable[Union[bytes], Any]]) -> Any
+        # type: (bool, Optional[Callable[bytes, Any]]) -> Any
         """
         Return an object constructed from the artifact file
 
@@ -156,7 +156,7 @@ class Artifact(object):
         pointing to a local copy of the artifacts file (or directory) will be returned
 
         :param bool force_download: download file from remote even if exists in local cache
-        :param Callable[Union[bytes], Any] deserialization_function: A deserialization function that takes one parameter of type `bytes`,
+        :param Callable[bytes, Any] deserialization_function: A deserialization function that takes one parameter of type `bytes`,
             which represents the serialized object. This function should return the deserialized object.
             Useful when the artifact was uploaded using a custom serialization function when calling the
             `Task.upload_artifact` method with the `serialization_function` argument.
@@ -426,9 +426,9 @@ class Artifacts(object):
                 artifact_type_data.preview = preview or str(artifact_object.__repr__())[:self.max_preview_size_bytes]
             except Exception:
                 artifact_type_data.preview = ""
-            override_filename_ext_in_uri = ""
-            override_filename_in_uri = name
-            fd, local_filename = mkstemp(prefix=quote(name, safe="") + ".")
+            override_filename_ext_in_uri = extension_name or ""
+            override_filename_in_uri = name + override_filename_ext_in_uri
+            fd, local_filename = mkstemp(prefix=quote(name, safe="") + ".", suffix=override_filename_ext_in_uri)
             os.close(fd)
             # noinspection PyBroadException
             try:
diff --git a/clearml/binding/fire_bind.py b/clearml/binding/fire_bind.py
index fb59f5a7..969cec1c 100644
--- a/clearml/binding/fire_bind.py
+++ b/clearml/binding/fire_bind.py
@@ -6,12 +6,24 @@ except ImportError:
     fire = None
 
 import inspect
-from types import SimpleNamespace
 from .frameworks import _patched_call  # noqa
 from ..config import get_remote_task_id, running_remotely
 from ..utilities.dicts import cast_str_to_bool
 
 
+class SimpleNamespace(object):
+    def __init__(self, **kwargs):
+        self.__dict__.update(kwargs)
+
+    def __repr__(self):
+        keys = sorted(self.__dict__)
+        items = ("{}={!r}".format(k, self.__dict__[k]) for k in keys)
+        return "{}({})".format(type(self).__name__, ", ".join(items))
+
+    def __eq__(self, other):
+        return self.__dict__ == other.__dict__
+
+
 class PatchFire:
     _args = {}
     _command_type = "fire.Command"
@@ -67,22 +79,22 @@ class PatchFire:
         else:
             args[cls._section_name + cls._args_sep + cls.__current_command] = True
             parameters_types[cls._section_name + cls._args_sep + cls.__current_command] = cls._command_type
-            args = {
-                **args,
-                **{
+            args.update(
+                {
                     cls._section_name + cls._args_sep + cls.__current_command + cls._args_sep + k: v
                     for k, v in cls._args.items()
                     if k in (PatchFire.__command_args.get(cls.__current_command) or [])
-                },
-                **{
+                }
+            )
+            args.update(
+                {
                     cls._section_name + cls._args_sep + k: v
                     for k, v in cls._args.items()
                     if k not in (PatchFire.__command_args.get(cls.__current_command) or [])
-                },
-            }
-            parameters_types = {
-                **parameters_types,
-                **{
+                }
+            )
+            parameters_types.update(
+                {
                     cls._section_name
                     + cls._args_sep
                     + cls.__current_command
@@ -90,13 +102,15 @@ class PatchFire:
                     + k: cls._command_arg_type_template % cls.__current_command
                     for k in cls._args.keys()
                     if k in (PatchFire.__command_args.get(cls.__current_command) or [])
-                },
-                **{
+                }
+            )
+            parameters_types.update(
+                {
                     cls._section_name + cls._args_sep + k: cls._shared_arg_type
                     for k in cls._args.keys()
                     if k not in (PatchFire.__command_args.get(cls.__current_command) or [])
-                },
-            }
+                }
+            )
         for command in cls.__commands:
             if command == cls.__current_command:
                 continue
@@ -114,8 +128,8 @@ class PatchFire:
                 + k: cls._command_arg_type_template % command
                 for k in (cls.__command_args.get(command) or [])
             }
-            args = {**args, **unused_command_args}
-            parameters_types = {**parameters_types, **unused_paramenters_types}
+            args.update(unused_command_args)
+            parameters_types.update(unused_paramenters_types)
 
         # noinspection PyProtectedMember
         cls._current_task._set_parameters(
@@ -186,7 +200,8 @@ class PatchFire:
         fn_spec = fire.inspectutils.GetFullArgSpec(component)
         parse = fire.core._MakeParseFn(fn, metadata)  # noqa
         (parsed_args, parsed_kwargs), _, _, _ = parse(args_)
-        PatchFire._args = {**PatchFire._args, **{k: v for k, v in zip(fn_spec.args, parsed_args)}, **parsed_kwargs}
+        PatchFire._args.update({k: v for k, v in zip(fn_spec.args, parsed_args)})
+        PatchFire._args.update(parsed_args)
         PatchFire._update_task_args()
         return original_fn(component, args_, component_trace, treatment, target, *args, **kwargs)
 
diff --git a/clearml/datasets/dataset.py b/clearml/datasets/dataset.py
index b84f91cb..f42edcb2 100644
--- a/clearml/datasets/dataset.py
+++ b/clearml/datasets/dataset.py
@@ -3013,7 +3013,7 @@ class Dataset(object):
                 only_fields=["id", "runtime.version"],
                 search_hidden=True,
                 _allow_extra_fields_=True,
-                **dataset_filter,
+                **dataset_filter
             )
         except Exception:
             datasets = []
diff --git a/clearml/storage/helper.py b/clearml/storage/helper.py
index 601d97bd..459794eb 100644
--- a/clearml/storage/helper.py
+++ b/clearml/storage/helper.py
@@ -1255,8 +1255,8 @@ class _HttpDriver(_Driver):
 
         headers = {
             'Content-Type': m.content_type,
-            **(container.get_headers(url) or {}),
         }
+        headers.update(container.get_headers(url) or {})
 
         if hasattr(iterator, 'tell') and hasattr(iterator, 'seek'):
             pos = iterator.tell()
@@ -1537,9 +1537,9 @@ class _Boto3Driver(_Driver):
         stream = _Stream(iterator)
         try:
             extra_args = {
-                'ContentType': get_file_mimetype(object_name),
-                **(container.config.extra_args or {})
+                'ContentType': get_file_mimetype(object_name)
             }
+            extra_args.update(container.config.extra_args or {})
             container.bucket.upload_fileobj(stream, object_name, Config=boto3.s3.transfer.TransferConfig(
                 use_threads=container.config.multipart,
                 max_concurrency=self._max_multipart_concurrency if container.config.multipart else 1,
@@ -1556,9 +1556,9 @@ class _Boto3Driver(_Driver):
         import boto3.s3.transfer
         try:
             extra_args = {
-                'ContentType': get_file_mimetype(object_name or file_path),
-                **(container.config.extra_args or {})
+                'ContentType': get_file_mimetype(object_name or file_path)
             }
+            extra_args.update(container.config.extra_args or {})
             container.bucket.upload_file(file_path, object_name, Config=boto3.s3.transfer.TransferConfig(
                 use_threads=container.config.multipart,
                 max_concurrency=self._max_multipart_concurrency if container.config.multipart else 1,
diff --git a/clearml/task.py b/clearml/task.py
index a6ad107d..31a19429 100644
--- a/clearml/task.py
+++ b/clearml/task.py
@@ -1920,6 +1920,7 @@ class Task(_Task):
         - pandas.DataFrame - ``.csv.gz``, ``.parquet``, ``.feather``, ``.pickle`` (default ``.csv.gz``)
         - numpy.ndarray - ``.npz``, ``.csv.gz`` (default ``.npz``)
         - PIL.Image - whatever extensions PIL supports (default ``.png``)
+        - In case the ``serialization_function`` argument is set - any extension is supported
 
         :param Callable[Any, Union[bytes, bytearray]] serialization_function: A serialization function that takes one
             parameter of any types which is the object to be serialized. The function should return a `bytes` or `bytearray`
diff --git a/clearml/utilities/version.py b/clearml/utilities/version.py
index 0b21e687..16fa152e 100644
--- a/clearml/utilities/version.py
+++ b/clearml/utilities/version.py
@@ -19,7 +19,7 @@ class InvalidVersion(ValueError):
 
 
 @attrs
-class _Version:
+class _Version(object):
     epoch = attrib()
     release = attrib()
     dev = attrib()
diff --git a/requirements.txt b/requirements.txt
index b669a62f..00c28ae8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,7 +11,8 @@ Pillow>=4.1.1
 psutil>=3.4.2
 pyparsing>=2.0.3
 python-dateutil>=2.6.1
-pyjwt>=2.4.0,<2.5.0
+pyjwt>=2.4.0,<2.5.0 ; python_version > '3.5'
+pyjwt>=1.6.4,<2.0.0 ; python_version <= '3.5'
 PyYAML>=3.12
 requests>=2.20.0
 six>=1.13.0
diff --git a/setup.py b/setup.py
index ee90ab63..41213336 100644
--- a/setup.py
+++ b/setup.py
@@ -6,10 +6,11 @@ https://github.com/allegroai/clearml
 import os.path
 # Always prefer setuptools over distutils
 from setuptools import setup, find_packages
+import codecs
 
 
 def read_text(filepath):
-    with open(filepath, "r", encoding="utf-8") as f:
+    with codecs.open(filepath, "r", encoding="utf-8") as f:
         return f.read()