diff --git a/setup.py b/setup.py
index 3e22b7c4..d50aeba1 100644
--- a/setup.py
+++ b/setup.py
@@ -82,7 +82,7 @@ setup(
     install_requires=[
         "graphql-core>=3.0.0a0,<4",
         "graphql-relay>=3.0.0a0,<4",
-        "aniso8601>=6,<8",
+        "aniso8601>=6,<9",
     ],
     tests_require=tests_require,
     extras_require={"test": tests_require},