diff --git a/var/spack/repos/builtin/packages/py-distributed/package.py b/var/spack/repos/builtin/packages/py-distributed/package.py
index 436078855d..93c2825fc3 100644
--- a/var/spack/repos/builtin/packages/py-distributed/package.py
+++ b/var/spack/repos/builtin/packages/py-distributed/package.py
@@ -12,6 +12,7 @@ class PyDistributed(PythonPackage):
     homepage = "https://distributed.dask.org/"
     pypi = "distributed/distributed-2.10.0.tar.gz"
 
+    version('2020.12.0', sha256='2a0b6acc921cd4e0143a7c4383cdcbed7defbc4bd9dc3aab0c7f1c45f14f80e1')
     version('2.10.0', sha256='2f8cca741a20f776929cbad3545f2df64cf60207fb21f774ef24aad6f6589e8b')
     version('1.28.1', sha256='3bd83f8b7eb5938af5f2be91ccff8984630713f36f8f66097e531a63f141c48a')
 
@@ -20,14 +21,21 @@ class PyDistributed(PythonPackage):
     depends_on('py-setuptools', type=('build', 'run'))
 
     depends_on('py-click@6.6:', type=('build', 'run'))
-    depends_on('py-cloudpickle@0.2.2:', type=('build', 'run'))
-    depends_on('py-msgpack', type=('build', 'run'))
+    depends_on('py-cloudpickle@0.2.2:', type=('build', 'run'), when='@:2.16.0')
+    depends_on('py-cloudpickle@1.3.0:', type=('build', 'run'), when='@2.17.0:2.20.0')
+    depends_on('py-cloudpickle@1.5.0:', type=('build', 'run'), when='@2.21.0:')
+    depends_on('py-contextvars', type=('build', 'run'), when='^python@:3.6')
+    depends_on('py-msgpack', type=('build', 'run'), when='@:2.10.0')
+    depends_on('py-msgpack@0.6.0:', type=('build', 'run'), when='@2.11.0:')
     depends_on('py-psutil@5.0:', type=('build', 'run'))
     depends_on('py-six', type=('build', 'run'), when='@:1')
     depends_on('py-sortedcontainers@:1.999,2.0.2:', type=('build', 'run'))
-    depends_on('py-tblib', type=('build', 'run'))
-    depends_on('py-toolz@0.7.4:', type=('build', 'run'))
-    depends_on('py-tornado@5:', type=('build', 'run'))
+    depends_on('py-tblib', type=('build', 'run'), when='@:2.10.0')
+    depends_on('py-tblib@1.6.0:', type=('build', 'run'), when='@2.11.0:')
+    depends_on('py-toolz@0.7.4:', type=('build', 'run'), when='@:2.12.0')
+    depends_on('py-toolz@0.8.2:', type=('build', 'run'), when='@2.13.0:')
+    depends_on('py-tornado@5:', type=('build', 'run'), when='^python@:3.7')
+    depends_on('py-tornado@6.0.3:', type=('build', 'run'), when='^python@3.8:')
     depends_on('py-zict@0.1.3:', type=('build', 'run'))
     depends_on('py-pyyaml', type=('build', 'run'))
     depends_on('py-futures', when='@:1 ^python@2.7:2.8', type=('build', 'run'))