diff --git a/.github/workflows/test_and_publish.yml b/.github/workflows/test_and_publish.yml
index 9a3c898..e2519a7 100644
--- a/.github/workflows/test_and_publish.yml
+++ b/.github/workflows/test_and_publish.yml
@@ -13,6 +13,10 @@ on:
   # Allow manual runs through the web UI
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   test:
     uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@v1
diff --git a/pytest_mpl/plugin.py b/pytest_mpl/plugin.py
index 7b59184..c5b9574 100644
--- a/pytest_mpl/plugin.py
+++ b/pytest_mpl/plugin.py
@@ -57,11 +57,7 @@
   Actual shape: {actual_shape}
     {actual_path}"""
 
-_pytest_version = Version(pytest.__version__)
-PYTEST_LT_7 = _pytest_version < Version("7.0.0")
-PYTEST_GE_8_0 = any([_pytest_version.is_devrelease,
-                     _pytest_version.is_prerelease,
-                     _pytest_version >= Version('8.0')])
+PYTEST_LT_7 = Version(pytest.__version__) < Version("7.0.0")
 
 # The following are the subsets of formats supported by the Matplotlib image
 # comparison machinery