diff --git a/.github/workflows/generated-bindings-ci.yml b/.github/workflows/generated-bindings-ci.yml
index 259473a..5d04034 100644
--- a/.github/workflows/generated-bindings-ci.yml
+++ b/.github/workflows/generated-bindings-ci.yml
@@ -193,6 +193,10 @@ jobs:
         if: matrix.v-channel == 'stable' || steps.setup_v_source.outcome == 'success'
         shell: bash
         run: v run setup.vsh --check
+      - name: Test runtime probe execution and working directory
+        if: matrix.v-channel == 'stable'
+        shell: bash
+        run: python ci/test_setup_runtime.py --cc "${{ matrix.compiler }}"
       - name: Accept old installed headers with bundled build inputs
         if: runner.os == 'Linux' && matrix.v-channel == 'stable'
         shell: bash
diff --git a/ci/test_setup_runtime.py b/ci/test_setup_runtime.py
new file mode 100644
index 0000000..57f6bd8
--- /dev/null
+++ b/ci/test_setup_runtime.py
@@ -0,0 +1,52 @@
+"""Exercise setup's runtime probe without depending on a GPU or installed SDK."""
+
+import argparse
+import os
+from pathlib import Path
+import shutil
+import subprocess
+import tempfile
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('--v', default=os.environ.get('VEXE', 'v'))
+    parser.add_argument('--cc', default='msvc' if os.name == 'nt' else 'gcc')
+    args = parser.parse_args()
+    root = Path(__file__).resolve().parents[1]
+    compiler = shutil.which(args.v) or str(Path(args.v).resolve())
+    suffix = '.exe' if os.name == 'nt' else ''
+    with tempfile.TemporaryDirectory(prefix='vulkan setup with spaces ') as temporary:
+        work = Path(temporary)
+        probe_source = work / 'probe.v'
+        probe_source.write_text('''import os
+fn main() {
+    assert os.args[1..] == ['--summary']
+    assert os.real_path(os.getwd()) == os.real_path(os.temp_dir())
+    os.write_file(os.getenv('PROBE_MARKER'), os.getwd()) or { panic(err) }
+    if os.getenv('PROBE_FAIL') == '1' { exit(23) }
+    println('GPU0: fixture')
+}
+''', encoding='utf-8')
+        probe = work / ('vulkaninfo' + suffix)
+        subprocess.run([compiler, '-cc', args.cc, '-o', str(probe), str(probe_source)],
+                       check=True, cwd=root)
+        marker = work / 'ran.txt'
+        env = dict(os.environ, PATH=str(work) + os.pathsep + os.environ['PATH'],
+                   PROBE_MARKER=str(marker))
+        for failure in ['0', '1']:
+            env['PROBE_FAIL'] = failure
+            result = subprocess.run([compiler, '-cc', args.cc, 'run', str(root / 'setup.vsh'),
+                                     '--check'], cwd=root, env=env,
+                                    capture_output=True, text=True, check=True)
+            print(result.stdout)
+            assert marker.is_file(), 'vulkaninfo never ran'
+            expected = ('[ok]       Vulkan loader enumerated a physical device' if failure == '0'
+                        else '[warning]  vulkaninfo is installed, but no usable device was enumerated')
+            assert expected in result.stdout, result.stdout + result.stderr
+            marker.unlink()
+    print('Setup runtime probe tests passed.')
+
+
+if __name__ == '__main__':
+    main()
diff --git a/setup.vsh b/setup.vsh
index da49665..9f80013 100644
--- a/setup.vsh
+++ b/setup.vsh
@@ -240,7 +240,17 @@ fn check() bool {
 	if command_exists('vulkaninfo') {
 		// Some SDK builds write their update manifest into the process working
 		// directory. Keep diagnostics from leaving residue in the user's repo.
-		result := os.execute('cd ${os.quoted_path(os.temp_dir())} && vulkaninfo --summary')
+		original_directory := os.getwd()
+		os.chdir(os.temp_dir()) or {
+			println('[warning]  Could not enter the temporary directory for Vulkan diagnostics: ${err}')
+			return ok
+		}
+		defer {
+			os.chdir(original_directory) or {}
+		}
+		// V's Windows os.execute rejects shell command chaining. Change the
+		// directory through the OS API so the probe actually runs on Windows.
+		result := os.execute('vulkaninfo --summary')
 		if result.exit_code == 0 {
 			println('[ok]       Vulkan loader enumerated a physical device')
 		} else {