diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 5b515c3..5aae0dc 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -58,8 +58,6 @@ jobs:
         uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
         with:
           python_version: "3.7"
-      - name: Install graphviz on Linux
-        run: sudo apt install -y graphviz
 
       - name: Install normally
         run: make install
@@ -86,8 +84,6 @@ jobs:
     steps:
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
       - uses: jupyterlab/maintainer-tools/.github/actions/test-sdist@v1
-      - name: Install graphviz on Linux
-        run: sudo apt install -y graphviz
 
   link_check:
     runs-on: ubuntu-latest
diff --git a/metakernel/magics/tests/test_dot_magic.py b/metakernel/magics/tests/test_dot_magic.py
index 829b9eb..e40920f 100644
--- a/metakernel/magics/tests/test_dot_magic.py
+++ b/metakernel/magics/tests/test_dot_magic.py
@@ -1,11 +1,13 @@
-import sys
+import shutil
 
 from metakernel.tests.utils import (get_kernel, get_log_text, 
                                     clear_log_text, EvalKernel)
 
 import pytest
 
-@pytest.mark.skipif(sys.platform != "linux", reason="Requires dot from grahviz")
+NO_DOT = shutil.which("dot") is None
+
+@pytest.mark.skipif(NO_DOT, reason="Requires dot from graphviz")
 def test_dot_magic_cell():
     kernel = get_kernel(EvalKernel)
     kernel.do_execute("""%%dot
@@ -16,7 +18,7 @@ def test_dot_magic_cell():
     text = get_log_text(kernel)
     assert "Display Data" in text, text
 
-@pytest.mark.skipif(sys.platform != "linux", reason="Requires dot from grahviz")
+@pytest.mark.skipif(NO_DOT, reason="Requires dot from graphviz")
 def test_dot_magic_line():
     kernel = get_kernel(EvalKernel)
     kernel.do_execute("%dot graph A { a->b };")