diff --git a/aiopg/connection.py b/aiopg/connection.py
index ca32bda0..dfbec5a7 100755
--- a/aiopg/connection.py
+++ b/aiopg/connection.py
@@ -834,10 +834,13 @@ def _ready(weak_self: "weakref.ref[Any]") -> None:
                     self._writing = False
             elif state == psycopg2.extensions.POLL_WRITE:
                 if not self._writing:
-                    self._loop.add_writer(
-                        self._fileno, self._ready, weak_self  # type: ignore
-                    )
-                    self._writing = True
+                    try:
+                        self._loop.add_writer(
+                            self._fileno, self._ready, weak_self  # type: ignore
+                        )
+                        self._writing = True
+                    except OSError as e:
+                        waiter.set_exception(e)
             elif state == psycopg2.extensions.POLL_ERROR:
                 self._fatal_error(
                     "Fatal error on aiopg connection: "
diff --git a/setup.py b/setup.py
index 6cd4ccef..812a4440 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@
 
 from setuptools import setup, find_packages
 
-install_requires = ["psycopg2-binary>=2.8.4", "async_timeout>=3.0,<4.0"]
+install_requires = ["psycopg2-binary>=2.8.4", "async_timeout>=3.0,<5.0"]
 extras_require = {"sa": ["sqlalchemy[postgresql_psycopg2binary]>=1.3,<1.5"]}