diff --git a/CHANGES.md b/CHANGES.md
index a2b44c4..14efee2 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -13,6 +13,7 @@
 * Update profilehooks module 1.10.1 (fdbf19d) to 1.11.0 (e17f378)
 * Update scandir 1.9.0 (9ab3d1f) to 1.10.0 (982e6ba)
 * Update Six compatibility library 1.12.0 (d927b9e) to 1.12.0 (8da94b8)
+* Update Tornado Web Server 5.1.1 (cc2cf07) to 5.1.1 (a99f1471)
 
 
 [develop changelog]
diff --git a/lib/tornado/util.py b/lib/tornado/util.py
index a42ebeb..151b0d8 100644
--- a/lib/tornado/util.py
+++ b/lib/tornado/util.py
@@ -59,7 +59,7 @@ else:
     import datetime  # noqa
     import types  # noqa
     from typing import Any, AnyStr, Union, Optional, Dict, Mapping  # noqa
-    from typing import Tuple, Match, Callable  # noqa
+    from typing import List, Tuple, Match, Callable  # noqa
 
     if PY3:
         _BaseString = str
@@ -252,7 +252,7 @@ _re_unescape_pattern = re.compile(r'\\(.)', re.DOTALL)
 
 def re_unescape(s):
     # type: (str) -> str
-    """Unescape a string escaped by `re.escape`.
+    r"""Unescape a string escaped by `re.escape`.
 
     May raise ``ValueError`` for regular expressions which could not
     have been produced by `re.escape` (for example, strings containing
diff --git a/lib/tornado/web.py b/lib/tornado/web.py
index 6760b0b..4340b16 100644
--- a/lib/tornado/web.py
+++ b/lib/tornado/web.py
@@ -1887,7 +1887,7 @@ class _ApplicationRouter(ReversibleRuleRouter):
 
 
 class Application(ReversibleRouter):
-    """A collection of request handlers that make up a web application.
+    r"""A collection of request handlers that make up a web application.
 
     Instances of this class are callable and can be passed directly to
     HTTPServer to serve the application::
diff --git a/lib/tornado/websocket.py b/lib/tornado/websocket.py
index 0b994fc..7b77850 100644
--- a/lib/tornado/websocket.py
+++ b/lib/tornado/websocket.py
@@ -751,10 +751,14 @@ class WebSocketProtocol13(WebSocketProtocol):
         self.stream = self.handler.stream
 
         self.start_pinging()
-        open_result = self._run_callback(self.handler.open, *self.handler.open_args,
-                                         **self.handler.open_kwargs)
-        if open_result is not None:
-            yield open_result
+        try:
+            open_result = self.handler.open(*self.handler.open_args, **self.handler.open_kwargs)
+            if open_result is not None:
+                yield open_result
+        except Exception:
+            self.handler.log_exception(*sys.exc_info())
+            self._abort()
+
         yield self._receive_frame_loop()
 
     def _parse_extensions_header(self, headers):