diff --git a/tck/src/main/java/org/reactivestreams/tck/SubscriberWhiteboxVerification.java b/tck/src/main/java/org/reactivestreams/tck/SubscriberWhiteboxVerification.java
index a22354a4..57970c46 100644
--- a/tck/src/main/java/org/reactivestreams/tck/SubscriberWhiteboxVerification.java
+++ b/tck/src/main/java/org/reactivestreams/tck/SubscriberWhiteboxVerification.java
@@ -539,6 +539,7 @@ public WhiteboxTestStage(TestEnvironment env, boolean runDefaultInit) throws Int
         probe = new WhiteboxSubscriberProbe<T>(env, subscriber);
         subscribe(createSubscriber(probe));
         probe.puppet.expectCompletion(env.defaultTimeoutMillis(), String.format("Subscriber %s did not `registerOnSubscribe`", sub()));
+        env.verifyNoAsyncErrorsNoDelay();
       }
     }
 
diff --git a/tck/src/test/java/org/reactivestreams/tck/SubscriberNoRegisterOnSubscribeTest.java b/tck/src/test/java/org/reactivestreams/tck/SubscriberNoRegisterOnSubscribeTest.java
new file mode 100644
index 00000000..a3f74795
--- /dev/null
+++ b/tck/src/test/java/org/reactivestreams/tck/SubscriberNoRegisterOnSubscribeTest.java
@@ -0,0 +1,185 @@
+/************************************************************************
+ * Licensed under Public Domain (CC0)                                    *
+ *                                                                       *
+ * To the extent possible under law, the person who associated CC0 with  *
+ * this code has waived all copyright and related or neighboring         *
+ * rights to this code.                                                  *
+ *                                                                       *
+ * You should have received a copy of the CC0 legalcode along with this  *
+ * work. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.*
+ ************************************************************************/
+
+package org.reactivestreams.tck;
+
+import org.reactivestreams.*;
+import org.testng.annotations.Test;
+
+/**
+ * This test verifies that the SubscriberWhiteboxVerification reports that
+ * WhiteboxSubscriberProbe.registerOnSubscribe was not called during the setup
+ * of each test.
+ */
+@Test
+public class SubscriberNoRegisterOnSubscribeTest extends SubscriberWhiteboxVerification<Integer> {
+
+    public SubscriberNoRegisterOnSubscribeTest() {
+        super(new TestEnvironment());
+    }
+
+    @Override
+    public Subscriber<Integer> createSubscriber(final WhiteboxSubscriberProbe<Integer> probe) {
+        return new Subscriber<Integer>() {
+            @Override
+            public void onSubscribe(final Subscription s) {
+                // deliberately not calling probe.registerOnSubscribe()
+            }
+
+            @Override
+            public void onNext(Integer integer) {
+                probe.registerOnNext(integer);
+            }
+
+            @Override
+            public void onError(Throwable t) {
+                probe.registerOnError(t);
+            }
+
+            @Override
+            public void onComplete() {
+                probe.registerOnComplete();
+            }
+        };
+    }
+
+    @Override
+    public Integer createElement(int element) {
+        return element;
+    }
+
+    void assertMessage(AssertionError ex) {
+        String message = ex.toString();
+        if (!message.contains(("did not `registerOnSubscribe` within"))) {
+            throw ex;
+        }
+    }
+
+    @Test
+    @Override
+    public void required_exerciseWhiteboxHappyPath() throws Throwable {
+        try {
+            super.required_exerciseWhiteboxHappyPath();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec201_mustSignalDemandViaSubscriptionRequest() throws Throwable {
+        try {
+            super.required_spec201_mustSignalDemandViaSubscriptionRequest();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec205_mustCallSubscriptionCancelIfItAlreadyHasAnSubscriptionAndReceivesAnotherOnSubscribeSignal() throws Throwable {
+        try {
+            super.required_spec205_mustCallSubscriptionCancelIfItAlreadyHasAnSubscriptionAndReceivesAnotherOnSubscribeSignal();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec208_mustBePreparedToReceiveOnNextSignalsAfterHavingCalledSubscriptionCancel() throws Throwable {
+        try {
+            super.required_spec208_mustBePreparedToReceiveOnNextSignalsAfterHavingCalledSubscriptionCancel();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec209_mustBePreparedToReceiveAnOnCompleteSignalWithoutPrecedingRequestCall() throws Throwable {
+        try {
+            super.required_spec209_mustBePreparedToReceiveAnOnCompleteSignalWithoutPrecedingRequestCall();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec209_mustBePreparedToReceiveAnOnCompleteSignalWithPrecedingRequestCall() throws Throwable {
+        try {
+            super.required_spec209_mustBePreparedToReceiveAnOnCompleteSignalWithPrecedingRequestCall();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec210_mustBePreparedToReceiveAnOnErrorSignalWithoutPrecedingRequestCall() throws Throwable {
+        try {
+            super.required_spec210_mustBePreparedToReceiveAnOnErrorSignalWithoutPrecedingRequestCall();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec210_mustBePreparedToReceiveAnOnErrorSignalWithPrecedingRequestCall() throws Throwable {
+        try {
+            super.required_spec210_mustBePreparedToReceiveAnOnErrorSignalWithPrecedingRequestCall();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec213_onError_mustThrowNullPointerExceptionWhenParametersAreNull() throws Throwable {
+        try {
+            super.required_spec213_onError_mustThrowNullPointerExceptionWhenParametersAreNull();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec213_onNext_mustThrowNullPointerExceptionWhenParametersAreNull() throws Throwable {
+        try {
+            super.required_spec213_onNext_mustThrowNullPointerExceptionWhenParametersAreNull();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec213_onSubscribe_mustThrowNullPointerExceptionWhenParametersAreNull() throws Throwable {
+        try {
+            super.required_spec213_onSubscribe_mustThrowNullPointerExceptionWhenParametersAreNull();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+
+    @Test
+    @Override
+    public void required_spec308_requestMustRegisterGivenNumberElementsToBeProduced() throws Throwable {
+        try {
+            super.required_spec308_requestMustRegisterGivenNumberElementsToBeProduced();
+        } catch (AssertionError ex) {
+            assertMessage(ex);
+        }
+    }
+}