diff --git a/test/parallel/test-diagnostics-channel-object-channel-pub-sub.js b/test/parallel/test-diagnostics-channel-object-channel-pub-sub.js
index bae69b02415785..cbc5b4d2e9a953 100644
--- a/test/parallel/test-diagnostics-channel-object-channel-pub-sub.js
+++ b/test/parallel/test-diagnostics-channel-object-channel-pub-sub.js
@@ -37,3 +37,7 @@ channel.publish(input);
 // Should not publish after subscriber is unsubscribed
 channel.unsubscribe(subscriber);
 assert.ok(!channel.hasSubscribers);
+
+assert.throws(() => {
+  channel.subscribe(null);
+}, { code: 'ERR_INVALID_ARG_TYPE' });
diff --git a/test/parallel/test-diagnostics-channel-symbol-named.js b/test/parallel/test-diagnostics-channel-symbol-named.js
index b98c2a1ef3ec6c..96fe0fa53596e2 100644
--- a/test/parallel/test-diagnostics-channel-symbol-named.js
+++ b/test/parallel/test-diagnostics-channel-symbol-named.js
@@ -20,3 +20,9 @@ channel.subscribe(common.mustCall((message, name) => {
 }));
 
 channel.publish(input);
+
+{
+  assert.throws(() => {
+    dc.channel(null);
+  }, /ERR_INVALID_ARG_TYPE/);
+}