diff --git a/requirements.txt b/requirements.txt
index b4a78f25e9..a8df33ca2f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,8 +6,8 @@ scipy>=0.14.1,<1.7.0
 joblib
 scikit-learn>=0.24.0,<0.25.0
 
-dask
-distributed>=2.2.0
+dask<2021.07
+distributed>=2.2.0,<2021.07
 pyyaml
 pandas>=1.0
 liac-arff