diff --git a/requirements.txt b/requirements.txt
index cd82e6bca5..fc9245b33d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -60,3 +60,4 @@ disposable-email-domains
 # Uncomment the requirement for ldap3 if using ldap.
 # It is not included by default because of the GPL license conflict.
 # ldap3==2.2.4
+gevent==1.4.0