diff --git a/setup.py b/setup.py
index 950f4b28..26c473d6 100644
--- a/setup.py
+++ b/setup.py
@@ -16,7 +16,7 @@ import octoprint_setuptools
 INSTALL_REQUIRES = [
 	"flask>=0.11,<0.12",
 	"werkzeug>=0.11.1,<0.12",
-	"tornado>=4.0.2,<4.1",
+	"tornado>=4.4.2,<4.5",
 	"sockjs-tornado>=1.0.2,<1.1",
 	"PyYAML>=3.10,<3.11",
 	"Flask-Login>=0.3,<0.4",
diff --git a/src/octoprint/server/util/tornado.py b/src/octoprint/server/util/tornado.py
index 12ba3b9b..54eb0955 100644
--- a/src/octoprint/server/util/tornado.py
+++ b/src/octoprint/server/util/tornado.py
@@ -672,8 +672,10 @@ class CustomHTTPServer(tornado.httpserver.HTTPServer):
 
 	``default_max_body_size`` is the default maximum body size to apply if no specific one from ``max_body_sizes`` matches.
 	"""
+        def __init__(self, *args, **kwargs):
+                pass
 
-	def __init__(self, request_callback, no_keep_alive=False, io_loop=None,
+	def initialize(self, request_callback, no_keep_alive=False, io_loop=None,
 				 xheaders=False, ssl_options=None, protocol=None,
 				 decompress_request=False,
 				 chunk_size=None, max_header_size=None,