diff --git a/setup.py b/setup.py
index e02e9f9..2506d99 100644
--- a/setup.py
+++ b/setup.py
@@ -21,7 +21,7 @@
 DEPENDENCIES = (
     "cachetools>=2.0.0,<5.0",
     "pyasn1-modules>=0.2.1",
-    "rsa>=3.1.4,<4.1",
+    "rsa>=3.1.4,<5.0",
     "setuptools>=40.3.0",
     "six>=1.9.0",
 )