diff --git a/pytest_blockage.py b/pytest_blockage.py
index cd27240..b07db24 100644
--- a/pytest_blockage.py
+++ b/pytest_blockage.py
@@ -18,7 +18,12 @@ class MockSmtpCall(Exception):
     pass
 
 
-def block_http(whitelist):
+def http_fail(host):
+    logger.warning('Denied HTTP connection to: %s' % host)
+    raise MockHttpCall(host)
+
+
+def block_http_httplib(whitelist):
     def whitelisted(self, host, *args, **kwargs):
         try:
             string_type = basestring
@@ -26,8 +31,8 @@ def whitelisted(self, host, *args, **kwargs):
             # python3
             string_type = str
         if isinstance(host, string_type) and host not in whitelist:
-            logger.warning('Denied HTTP connection to: %s' % host)
-            raise MockHttpCall(host)
+            http_fail(host)
+
         logger.debug('Allowed HTTP connection to: %s' % host)
         return self.old(host, *args, **kwargs)
 
@@ -39,6 +44,34 @@ def whitelisted(self, host, *args, **kwargs):
         httplib.HTTPConnection.__init__ = whitelisted
 
 
+def block_http_aiohttp(whitelist):
+    try:
+        from aiohttp.client import ClientSession
+    except ImportError:
+        # no aiohttp installed
+        return
+
+    from yarl import URL
+
+    def patch(self, method, url, **kwargs):
+        yurl = URL(url)
+
+        if yurl.host not in whitelist:
+            http_fail(yurl.host)
+
+        return self.old_request(method, url, **kwargs)
+
+    if not getattr(ClientSession, 'blockage', False):
+        logger.debug('Monkey patching httplib')
+        ClientSession.old_request = ClientSession._request
+        ClientSession._request = patch
+
+
+def block_http(whitelist):
+    block_http_httplib(whitelist)
+    block_http_aiohttp(whitelist)
+
+
 def block_smtp(whitelist):
     def whitelisted(self, host, *args, **kwargs):
         if isinstance(host, basestring) and host not in whitelist: