diff --git a/.python-version b/.python-version
index eb39e53..cc1923a 100644
--- a/.python-version
+++ b/.python-version
@@ -1 +1 @@
-3.3
+3.8
diff --git a/README.md b/README.md
index efb8b58..64b5660 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
-Helium package for Sublime Text 3
+Helium package for Sublime Text
 ===
 
-Helium is a package for Sublime Text 3, which provides in-editor code execution and autocomplete in interaction with Jupyter kernels.
-The concept of an editor extension communicating Jupyter kernels is inspired by @nteract's splendid Atom package [Hydrogen](https://github.com/nteract/Hydrogen). I want something like it in Sublime Text 3, too.
+Helium is a package for Sublime Text, which provides in-editor code execution and autocomplete in interaction with Jupyter kernels.
+The concept of an editor extension communicating Jupyter kernels is inspired by @nteract's splendid Atom package [Hydrogen](https://github.com/nteract/Hydrogen). I want something like it in Sublime Text, too.
 
 Any feedback is highly welcome. I hope this package will help your life with ST3!
 
diff --git a/dependencies.json b/dependencies.json
index 642507d..da2ac48 100644
--- a/dependencies.json
+++ b/dependencies.json
@@ -1,30 +1,52 @@
 {
 	"windows": {
-		"*": [
+		"<4000": [
 			"dateutil",
 			"enum",
 			"python-six",
 			"pyzmq"
+		],
+		">=4000": [
+			"dateutil",
+			"python-six",
+			"pyzmq",
+			"tornado"
 		]
 	},
 	"osx": {
-		"*": [
+		"<4000": [
 			"dateutil",
 			"enum",
 			"pexpect",
 			"ptyprocess",
 			"python-six",
 			"pyzmq"
+		],
+		">=4000": [
+			"dateutil",
+			"pexpect",
+			"ptyprocess",
+			"python-six",
+			"pyzmq",
+			"tornado"
 		]
 	},
 	"linux": {
-		"*": [
+		"<4000": [
 			"dateutil",
 			"enum",
 			"pexpect",
 			"ptyprocess",
 			"python-six",
 			"pyzmq"
+		],
+		">=4000": [
+			"dateutil",
+			"pexpect",
+			"ptyprocess",
+			"python-six",
+			"pyzmq",
+			"tornado"
 		]
 	}
 }
\ No newline at end of file
diff --git a/lib/client/jupyter_client/manager.py b/lib/client/jupyter_client/manager.py
index 3df36fd..f3888f0 100644
--- a/lib/client/jupyter_client/manager.py
+++ b/lib/client/jupyter_client/manager.py
@@ -78,7 +78,7 @@ def _kernel_name_changed(self, name, old, new):
 
     @property
     def kernel_spec(self):
-        if self._kernel_spec is None and self.kernel_name is not '':
+        if self._kernel_spec is None and self.kernel_name != '':
             self._kernel_spec = self.kernel_spec_manager.get_kernel_spec(self.kernel_name)
         return self._kernel_spec
 
diff --git a/lib/client/traitlets/config/loader.py b/lib/client/traitlets/config/loader.py
index 803b362..c9ef77e 100644
--- a/lib/client/traitlets/config/loader.py
+++ b/lib/client/traitlets/config/loader.py
@@ -542,7 +542,7 @@ def _load_flag(self, cfg):
 # rejects:  --anything=anything
 #           --two.word
 
-flag_pattern = re.compile(r'\-\-?\w+[\-\w]*$')
+flag_pattern = re.compile(r'\-\-?\w[\-\w]*$')
 
 class KeyValueConfigLoader(CommandLineConfigLoader):
     """A config loader that loads key value pairs from the command line.
@@ -669,7 +669,7 @@ def load_config(self, argv=None, aliases=None, flags=None):
 
             elif flag_pattern.match(raw):
                 if item in flags:
-                    cfg,help = flags[item]
+                    cfg,_ = flags[item]
                     self._load_flag(cfg)
                 else:
                     raise ArgumentError("Unrecognized flag: '%s'"%raw)
@@ -792,7 +792,7 @@ def _add_arguments(self, aliases=None, flags=None):
                 nargs = '?'
             else:
                 nargs = None
-            if len(key) is 1:
+            if len(key) == 1:
                 paa('-'+key, '--'+key, type=text_type, dest=value, nargs=nargs)
             else:
                 paa('--'+key, type=text_type, dest=value, nargs=nargs)
@@ -801,7 +801,7 @@ def _add_arguments(self, aliases=None, flags=None):
                 #
                 self.alias_flags[self.aliases[key]] = value
                 continue
-            if len(key) is 1:
+            if len(key) == 1:
                 paa('-'+key, '--'+key, action='append_const', dest='_flags', const=value)
             else:
                 paa('--'+key, action='append_const', dest='_flags', const=value)