diff --git a/requirements.txt b/requirements.txt
index dc565dd..ecf5679 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,5 +3,5 @@ iso8601==0.1.11
 ndg-httpsclient==0.4.2
 pyasn1==0.1.9
 pyOpenSSL==18.0.0
-PyYAML==3.12
+PyYAML>=4.2b1
 requests==2.20.0