diff --git a/bigchaindb/web/websocket_server.py b/bigchaindb/web/websocket_server.py
index e47ef67a..3e5461ce 100644
--- a/bigchaindb/web/websocket_server.py
+++ b/bigchaindb/web/websocket_server.py
@@ -105,7 +105,7 @@ class Dispatcher:
 
             for _, websocket in self.subscribers.items():
                 for str_item in str_buffer:
-                    websocket.send_str(str_item)
+                    yield from websocket.send_str(str_item)
 
 
 @asyncio.coroutine
diff --git a/setup.py b/setup.py
index 02286b47..049c8a05 100644
--- a/setup.py
+++ b/setup.py
@@ -85,7 +85,7 @@ install_requires = [
     'gunicorn~=19.0',
     'jsonschema~=2.5.1',
     'pyyaml~=3.12',
-    'aiohttp~=2.3',
+    'aiohttp~=3.0',
     'python-rapidjson-schema==0.1.1',
     'bigchaindb-abci==0.5.1',
     'setproctitle~=1.1.0',