diff --git a/carsus_env3.yml b/carsus_env3.yml
index 05370c004..baba7c394 100644
--- a/carsus_env3.yml
+++ b/carsus_env3.yml
@@ -30,6 +30,7 @@ dependencies:
 
   # Analysis
   - jupyter
+  - jupyter_client=6  # jupyter/jupyter_client/issues/637
   - matplotlib
 
   # Documentation
diff --git a/setup.cfg b/setup.cfg
index 4e1b60041..917a42461 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -35,7 +35,7 @@ testpaths = "carsus" "docs"
 astropy_header = true
 # doctest_plus = enabled
 text_file_format = rst
-# addopts = --doctest-rst
+addopts = -p no:warnings # --doctest-rst
 
 [coverage:run]
 omit =