diff --git a/setup.py b/setup.py
index 21bac743..ebd4a831 100644
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@
         'protobuf>=3.8.0',
         'grpcio-tools>=1.12.1',
         'pysha3;python_version<"3.6"',
-
+        'pynacl>=1.4.0'
     ],
     classifiers=[
         'Programming Language :: Python :: 3',