diff --git a/setup.py b/setup.py
index 5da4aef8..e1843d70 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@ from setuptools import setup
 
 dependencies = [
     "aiter==0.13.20191203",  # Used for async generator tools
-    "blspy==0.1.20",  # Signature library
+    "blspy==0.1.21",  # Signature library
     "cbor2==5.1.0",  # Used for network wire format
     "clvm==0.4",  # contract language
     "PyYAML==5.3",  # Used for config file format