diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f0f2d68..9ba0469 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -70,6 +70,7 @@ jobs:
       matrix:
         toxenv:
           - flake8
+          - isort
 
     steps:
       - name: Git clone
diff --git a/tox.ini b/tox.ini
index 476d2c9..f0b8256 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,3 +20,8 @@ commands =
 deps = flake8
 skip_install = true
 commands = flake8 setup.py multiping.py
+
+[testenv:isort]
+deps = isort
+skip_install = true
+commands = isort {posargs: -c --diff multiping.py setup.py tests.py}