diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,6 +16,7 @@ python-dateutil==2.6.0
 pyusb==1.0.0
 rdflib==4.2.2
 requests==2.22.0
+rx==1.6.1
 scipy==1.3.0
 service_identity==18.1.0
 statprof==0.1.2