diff --git a/setup.cfg b/setup.cfg
index 9d00e30a9..aa3e9f760 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -21,7 +21,7 @@ install_requires =
   astropy>=5.0
   astropy-healpix>=0.6
   scipy>=1.5
-  dask[array]>=2020
+  dask[array]>=2021.8
   cloudpickle
   zarr
   fsspec
diff --git a/tox.ini b/tox.ini
index 6f4bb0bd7..cc387ab3f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -24,7 +24,7 @@ deps =
     oldestdeps: astropy==5.0.*
     oldestdeps: astropy-healpix==0.6
     oldestdeps: scipy==1.5.*
-    oldestdeps: dask==2020.12.*
+    oldestdeps: dask==2021.8.*
 
     devdeps: numpy>=0.0.dev0
     devdeps: scipy>=0.0.dev0