diff --git a/cts_runner/examples/hello-compute.js b/cts_runner/examples/hello-compute.js
index 9c4023ed5e3..a6f6ca400c3 100644
--- a/cts_runner/examples/hello-compute.js
+++ b/cts_runner/examples/hello-compute.js
@@ -112,8 +112,8 @@ function isTypedArrayEqual(a, b) {
 const actual = new Uint32Array(data);
 const expected = new Uint32Array([0, 2, 7, 55]);
 
-console.error("actual", actual);
-console.error("expected", expected);
+console.log("actual", actual);
+console.log("expected", expected);
 
 if (!isTypedArrayEqual(actual, expected)) {
   throw new TypeError("Actual does not equal expected!");
diff --git a/cts_runner/tests/features.js b/cts_runner/tests/features.js
new file mode 100644
index 00000000000..23b693a3aa5
--- /dev/null
+++ b/cts_runner/tests/features.js
@@ -0,0 +1,5 @@
+const adapter = await navigator.gpu.requestAdapter();
+
+if (adapter.features.has("mappable-primary-buffers")) {
+    throw new TypeError("Adapter should not report support for wgpu native-only features");
+}
diff --git a/cts_runner/tests/integration.rs b/cts_runner/tests/integration.rs
index 30057c3c0a5..199f00e6315 100644
--- a/cts_runner/tests/integration.rs
+++ b/cts_runner/tests/integration.rs
@@ -1,4 +1,13 @@
-use std::path::PathBuf;
+// Tests for cts_runner
+//
+// As of June 2025, these tests are not run in CI.
+
+use std::{
+    fmt::{self, Debug, Display},
+    path::PathBuf,
+    process::Command,
+    str,
+};
 
 pub fn target_dir() -> PathBuf {
     let current_exe = std::env::current_exe().unwrap();
@@ -15,13 +24,38 @@ pub fn cts_runner_exe_path() -> PathBuf {
     p
 }
 
-#[test]
-fn hello_compute_example() {
-    let output = std::process::Command::new(cts_runner_exe_path())
-        .arg("examples/hello-compute.js")
-        .spawn()
-        .unwrap()
-        .wait_with_output()
+pub struct JsError;
+
+impl Display for JsError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "JavaScript test returned an error")
+    }
+}
+
+impl Debug for JsError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
+type JsResult = Result<(), JsError>;
+
+fn exec_js_test(script: &str) -> JsResult {
+    let output = Command::new(cts_runner_exe_path())
+        .arg(script)
+        .output()
         .unwrap();
-    assert!(output.status.success())
+    println!("{}", str::from_utf8(&output.stdout).unwrap());
+    eprintln!("{}", str::from_utf8(&output.stderr).unwrap());
+    output.status.success().then_some(()).ok_or(JsError)
+}
+
+#[test]
+fn hello_compute_example() -> JsResult {
+    exec_js_test("examples/hello-compute.js")
+}
+
+#[test]
+fn features() -> JsResult {
+    exec_js_test("tests/features.js")
 }
diff --git a/deno_webgpu/adapter.rs b/deno_webgpu/adapter.rs
index d05dca749ab..d5916fb0677 100644
--- a/deno_webgpu/adapter.rs
+++ b/deno_webgpu/adapter.rs
@@ -84,6 +84,8 @@ impl GPUAdapter {
     fn features(&self, scope: &mut v8::HandleScope) -> v8::Global<v8::Object> {
         self.features.get(scope, |scope| {
             let features = self.instance.adapter_features(self.id);
+            // Only expose WebGPU features, not wgpu native-only features
+            let features = features & wgpu_types::Features::all_webgpu_mask();
             let features = features_to_feature_names(features);
             GPUSupportedFeatures::new(scope, features)
         })