diff --git a/CI_REQUIREMENTS.txt b/CI_REQUIREMENTS.txt
index d218dbc..e27efef 100644
--- a/CI_REQUIREMENTS.txt
+++ b/CI_REQUIREMENTS.txt
@@ -1,4 +1,3 @@
 typing >= 3.6 ; python_version < "3.8"
-greenlet <= 0.4.13
 gevent >= 1.2, <1.3.0 ; platform_python_implementation == "PyPy"
 gevent >= 1.2 ; platform_python_implementation != "PyPy"