diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d3019f8..87b3adc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -36,12 +36,15 @@ jobs:
         os: [ubuntu-latest]
         python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "pypy-3.9"]
         optional-deps: [true]
+        with-python-isal: [true]
         include:
         - os: macos-latest
           python-version: "3.10"
           optional-deps: true
+          with-python-isal: false
         - os: ubuntu-20.04
           python-version: "3.10"
+          with-python-isal: false
           optional-deps: false
         - os: ubuntu-20.04
           python-version: "3.10"
@@ -70,6 +73,10 @@ jobs:
       run: python -m pip install tox
     - name: Test
       run: tox -e py
+      if: matrix.with-python-isal
+    - name: Test without python-isal
+      run: tox -e no-isal
+      if: not matrix.with-python-isal
     - name: Test with zstandard
       if: matrix.with-zstandard
       run: tox -e zstd
diff --git a/tox.ini b/tox.ini
index c66aa54..3b2314d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -21,6 +21,11 @@ deps =
     {[testenv]deps}
     zstandard
 
+[testenv:no-isal]
+commands=
+    pip uninstall -y isal
+    {[testenv]commands}
+
 [testenv:black]
 basepython = python3.10
 deps = black==22.3.0