diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 19c054db..627b6087 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -33,6 +33,15 @@ jobs:
         run: |
             python -m pip install --upgrade pip
             pip install -e .[dev]
-      - name: Run tests
+      - name: Run tests (Linux)
+        if: startsWith(matrix.os, 'ubuntu')
         run: |
             pytest -n 16 -sv --cov=textworld --cov-report=term-missing --cov-fail-under=85 tests/ textworld/
+
+      # On MacOS, tests/test_sample_quests.py crashes when run concurrently with
+      # pytest-xdist (native rendering/Graphviz), so it is run serially instead.
+      - name: Run tests (MacOS)
+        if: startsWith(matrix.os, 'macos')
+        run: |
+            pytest -n 16 -sv --cov=textworld --cov-report= --ignore=tests/test_sample_quests.py tests/ textworld/
+            pytest -sv --cov=textworld --cov-append --cov-report=term-missing --cov-fail-under=85 tests/test_sample_quests.py
diff --git a/tests/test_sample_quests.py b/tests/test_sample_quests.py
index 41ec782b..1a2001e6 100644
--- a/tests/test_sample_quests.py
+++ b/tests/test_sample_quests.py
@@ -2,6 +2,7 @@
 # Licensed under the MIT license.
 
 import os
+import sys
 from os.path import join as pjoin
 from subprocess import check_output
 
@@ -17,7 +18,7 @@ def test_sample_quests():
         check_output(command).decode()
 
         script = pjoin(SCRIPTS_PATH, "sample_quests.py")
-        command = ["python", script, "--nb-quests", "10", "--quest-length", "10",
+        command = [sys.executable, script, "--nb-quests", "10", "--quest-length", "10",
                    "--quest-breadth", "5", "--output", tmpdir, game_file]
         stdout = check_output(command).decode()
         assert len(stdout) > 0