diff --git a/requirements.txt b/requirements.txt
index 12e48c8e6..7f1e2d8fd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -38,6 +38,10 @@ kombu>=3.0.7
 pika>=0.10.0
 pika-pool>=0.1.3
 
+# used by pika and zmq drivers
+futures>=3.0;python_version=='2.7' or python_version=='2.6'
+retrying>=1.2.3,!=1.3.0 # Apache-2.0
+
 # middleware
 oslo.middleware>=3.0.0 # Apache-2.0