diff --git a/requirements.txt b/requirements.txt
index e212c048..52e6ad11 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
-aiohttp<2.0.0 # sockjs doesn't support 2.0+
+aiohttp>=2.0.5
 jinja2>=2.9.0
-sockjs>=0.5.0
+# sockjs at head supports aiohttp 2.0, but not released yet.
+git+https://github.com/aio-libs/sockjs.git
 motor
 hoedown
 accept
diff --git a/vj4/app.py b/vj4/app.py
index ea1d692d..38cff9c5 100644
--- a/vj4/app.py
+++ b/vj4/app.py
@@ -1,5 +1,4 @@
 import asyncio
-import functools
 import logging
 from os import path
 
@@ -47,7 +46,8 @@ def __init__(self):
     # Initialize components.
     staticmanifest.init(static_path)
     locale.load_translations(translation_path)
-    self.loop.run_until_complete(asyncio.gather(tools.ensure_all_indexes(), bus.init()))
+    asyncio.get_event_loop().run_until_complete(
+        asyncio.gather(tools.ensure_all_indexes(), bus.init()))
     smallcache.init()
 
     # Load views.
@@ -101,12 +101,12 @@ def get(self, id, create=False, request=None):
                                     timeout=self.timeout, loop=self.loop, debug=self.debug))
         return self[id]
 
+    loop = asyncio.get_event_loop()
     sockjs.add_endpoint(Application(), handler, name=name, prefix=prefix,
-                        manager=Manager(name, Application(), handler, Application().loop))
-    sockjs.add_endpoint(Application(), handler,
-                        name=name + '_with_domain_id', prefix='/d/{domain_id}' + prefix,
-                        manager=Manager(name + '_with_domain_id', Application(), handler,
-                                        Application().loop))
+                        manager=Manager(name, Application(), handler, loop))
+    sockjs.add_endpoint(
+        Application(), handler, name=name + '_with_domain_id', prefix='/d/{domain_id}' + prefix,
+        manager=Manager(name + '_with_domain_id', Application(), handler, loop))
     return conn
 
   return decorate
diff --git a/vj4/handler/base.py b/vj4/handler/base.py
index 728a225d..2971a7f1 100644
--- a/vj4/handler/base.py
+++ b/vj4/handler/base.py
@@ -413,7 +413,7 @@ def wrapped(self, **kwargs):
 def get_argument(func):
   @functools.wraps(func)
   def wrapped(self, **kwargs):
-    return func(self, **kwargs, **self.request.GET)
+    return func(self, **kwargs, **self.request.query)
 
   return wrapped
 
diff --git a/vj4/handler/domain.py b/vj4/handler/domain.py
index d2be3698..2eaf6114 100644
--- a/vj4/handler/domain.py
+++ b/vj4/handler/domain.py
@@ -119,9 +119,9 @@ async def post_set_user(self, *, uid: int, role: str):
   @base.require_perm(builtin.PERM_EDIT_PERM)
   @base.require_csrf_token
   @base.sanitize
-  async def post_set_users(self, *, uid: int, role: str):
+  async def post_set_users(self, *, uid: int, role: str=None):
     try:
-      uids = map(int, self.request.POST.getall('uid'))
+      uids = map(int, (await self.request.post()).getall('uid'))
     except ValueError:
       raise error.ValidationError('uid')
     if role:
@@ -148,7 +148,7 @@ async def post(self, **kwargs):
     new_roles = dict()
     for role in self.domain['roles']:
       perms = 0
-      for perm in self.request.POST.getall(role, []):
+      for perm in (await self.request.post()).getall(role, []):
        perm = int(perm)
        if perm in builtin.PERMS_BY_KEY:
           perms |= perm
@@ -181,5 +181,5 @@ async def post_set(self, *, role: str, perm: int=builtin.DEFAULT_PERMISSIONS):
   @base.require_csrf_token
   @base.sanitize
   async def post_delete(self, *, role: str):
-    await domain.delete_roles(self.domain_id, self.request.POST.getall('role'))
+    await domain.delete_roles(self.domain_id, (await self.request.post()).getall('role'))
     self.json_or_redirect(self.url)
diff --git a/vj4/handler/fs.py b/vj4/handler/fs.py
index 6c83e933..5587e153 100644
--- a/vj4/handler/fs.py
+++ b/vj4/handler/fs.py
@@ -101,7 +101,8 @@ async def stream_data(self, *, secret: str, headers_only: bool=False):
     grid_out = await fs.get_by_secret(secret)
 
     self.response.content_type = grid_out.content_type or 'application/octet-stream'
-    self.response.content_length = grid_out.length
+    # FIXME(iceboy): For some reason setting response.content_length doesn't work in aiohttp 2.0.5.
+    self.response.headers['Content-Length'] = str(grid_out.length)
 
     # Cache control.
     self.response.last_modified = grid_out.upload_date
diff --git a/vj4/handler/problem.py b/vj4/handler/problem.py
index 15cb2fd2..b634afc7 100644
--- a/vj4/handler/problem.py
+++ b/vj4/handler/problem.py
@@ -233,8 +233,8 @@ async def post(self, *, pid: document.convert_doc_id, lang: str, code: str,
     pdoc = await problem.get(self.domain_id, pid)
     # don't need to check hidden status
     # create zip file, TODO(twd2): check file size
-    content = list(zip(self.request.POST.getall('data_input'),
-                       self.request.POST.getall('data_output')))
+    post = await self.request.post()
+    content = list(zip(post.getall('data_input'), post.getall('data_output')))
     output_buffer = io.BytesIO()
     zip_file = zipfile.ZipFile(output_buffer, 'a', zipfile.ZIP_DEFLATED)
     config_content = str(len(content)) + '\n'