diff --git a/requirements.txt b/requirements.txt
index 33f3531..de86347 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,3 +9,4 @@ cryptography==1.3
 PyYAML==3.11
 requests==2.9.1
 vcrpy==1.7.4
+vdf==2.0