diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4a2d423..8771f48 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -71,7 +71,14 @@ jobs:
 
   pytest:
     name: Pytest
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      # Keep both lanes reporting even when one fails — a Windows-only
+      # failure with a green ubuntu lane is exactly the signal this
+      # matrix exists to surface.
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
     steps:
       - uses: actions/checkout@v4
 
diff --git a/tests/server/test_published_setup_runner.py b/tests/server/test_published_setup_runner.py
index 06c31c9..9894292 100644
--- a/tests/server/test_published_setup_runner.py
+++ b/tests/server/test_published_setup_runner.py
@@ -907,11 +907,15 @@ def test_get_run_reports_execution_map_writer_filepath_when_saver_history_is_emp
 
         status = await runner.getRun(queued["runId"])
 
+        # build_pipeline_outputs canonicalizes paths to forward slashes on
+        # every platform, so the expected prefix must match — str(tmp_path)
+        # yields backslashes on Windows.
+        canonical_folder = str(output_folder).replace("\\", "/")
         assert status["outputs"][-1]["items"] == [
             {
                 "nodeId": "313",
                 "kind": "text",
-                "value": f"{output_folder}/v007/external_v007.png",
+                "value": f"{canonical_folder}/v007/external_v007.png",
             }
         ]
         assert makedirs_calls == []