diff --git a/.circleci/config.yml b/.circleci/config.yml
index 9f066cf60..8cdbed8f5 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -203,7 +203,7 @@ jobs:
 
       - restore_cache:
           name: "Restore dependencies cache."
-          key: python-<< parameters.tag >>-dependencies-v7
+          key: python-<< parameters.tag >>-dependencies-v8
 
       - install-dependencies:
           yttag: << parameters.yttag >>
@@ -212,7 +212,7 @@ jobs:
 
       - save_cache:
           name: "Save dependencies cache."
-          key: python-<< parameters.tag >>-dependencies-v7
+          key: python-<< parameters.tag >>-dependencies-v8
           paths:
             - ~/.cache/pip
             - ~/venv
@@ -272,14 +272,14 @@ jobs:
       - checkout
       - restore_cache:
           name: "Restore dependencies cache."
-          key: python-<< parameters.tag >>-dependencies-v7
+          key: python-<< parameters.tag >>-dependencies-v8
       - set-env
       - install-dependencies:
           yttag: "YT_HEAD"
       - configure-trident
       - save_cache:
           name: "Save dependencies cache."
-          key: python-<< parameters.tag >>-dependencies-v7
+          key: python-<< parameters.tag >>-dependencies-v8
           paths:
             - ~/.cache/pip
             - ~/venv
diff --git a/setup.py b/setup.py
index af22b1bdf..39c8c112b 100644
--- a/setup.py
+++ b/setup.py
@@ -46,7 +46,6 @@ def get_version(filename):
         "License :: OSI Approved :: BSD License",
         "Natural Language :: English",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
@@ -60,7 +59,7 @@ def get_version(filename):
     install_requires=[
         'astropy',
         'h5py',
-        'matplotlib',
+        'matplotlib<3.3.0',
         'numpy!=1.14.0',
         'requests',
         'scipy',