diff --git a/reference_implementation/requirements.txt b/reference_implementation/requirements.txt
index 5900da5..a15d514 100644
--- a/reference_implementation/requirements.txt
+++ b/reference_implementation/requirements.txt
@@ -1,3 +1,3 @@
 python-bitcoinlib==0.7.0
 pycrypto==2.6.1
-pytest==3.0.6
+pytest==9.0.3