diff --git a/setup.py b/setup.py
index 3ca46de..1b6025a 100644
--- a/setup.py
+++ b/setup.py
@@ -40,7 +40,7 @@ def read(fname):
                             'ipython >= 6.0',
                             'nbformat',
                             'nbconvert',
-                            'jupyter_client',
+                            'jupyter_client < 6.0',
                             'ipykernel'],
       extras_require = {'test': ['scipy', 'matplotlib', 'coverage',
                                    'ipython', 'nose', 'notebook'],