diff --git a/requirements.txt b/requirements.txt
index 7244e7db..840a9b3d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,8 @@
 blake2b-py
-cytools<0.12.0
 coloredlogs>=10.0
 coincurve>=13.0.0
+cython
+cytoolz<0.12.0
 asn1crypto>=0.22.0
 configparser>=3.5.0
 coverage>6.0
diff --git a/setup.py b/setup.py
index f593daef..2f50e680 100755
--- a/setup.py
+++ b/setup.py
@@ -53,9 +53,7 @@ REQUIRED = get_requirements()
 TESTS_REQUIRE = ["mypy==0.782", "pytest>=3.6.0", "pytest_mock", "pytest-cov"]
 
 # What packages are optional?
-EXTRAS = {
-    # 'fancy feature': ['django'],
-}
+EXTRAS = {}
 
 # If version is set to None then it will be fetched from __version__.py
 VERSION = None