diff --git a/spring-modulith-events/spring-modulith-events-core/src/main/java/org/springframework/modulith/events/support/CompletionRegisteringAdvisor.java b/spring-modulith-events/spring-modulith-events-core/src/main/java/org/springframework/modulith/events/support/CompletionRegisteringAdvisor.java
index 36054b8a..c1c75614 100644
--- a/spring-modulith-events/spring-modulith-events-core/src/main/java/org/springframework/modulith/events/support/CompletionRegisteringAdvisor.java
+++ b/spring-modulith-events/spring-modulith-events-core/src/main/java/org/springframework/modulith/events/support/CompletionRegisteringAdvisor.java
@@ -16,6 +16,7 @@
 package org.springframework.modulith.events.support;
 
 import java.lang.reflect.Method;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.Supplier;
 
 import org.aopalliance.aop.Advice;
@@ -31,6 +32,7 @@ import org.springframework.aop.support.annotation.AnnotationMatchingPointcut;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.lang.NonNull;
+import org.springframework.lang.Nullable;
 import org.springframework.modulith.events.core.EventPublicationRegistry;
 import org.springframework.modulith.events.core.PublicationTargetIdentifier;
 import org.springframework.transaction.event.TransactionPhase;
@@ -164,25 +166,30 @@ public class CompletionRegisteringAdvisor extends AbstractPointcutAdvisor {
 
 			Object result = null;
 			var method = invocation.getMethod();
+			var argument = invocation.getArguments()[0];
 
 			try {
-				result = invocation.proceed();
-			} catch (Exception o_O) {
 
-				if (LOG.isDebugEnabled()) {
-					LOG.debug("Invocation of listener {} failed. Leaving event publication uncompleted.", method, o_O);
-				} else {
-					LOG.info("Invocation of listener {} failed with message {}. Leaving event publication uncompleted.",
-							method, o_O.getMessage());
+				result = invocation.proceed();
+
+				if (result instanceof CompletableFuture<?> future) {
+
+					return future
+							.thenAccept(it -> markCompleted(method, argument))
+							.exceptionallyCompose(it -> {
+								handleFailure(method, it);
+								return CompletableFuture.failedFuture(it);
+							});
 				}
 
+			} catch (Throwable o_O) {
+
+				handleFailure(method, o_O);
+
 				throw o_O;
 			}
 
-			// Mark publication complete if the method is a transactional event listener.
-			String adapterId = ADAPTERS.get(method).getListenerId();
-			PublicationTargetIdentifier identifier = PublicationTargetIdentifier.of(adapterId);
-			registry.get().markCompleted(invocation.getArguments()[0], identifier);
+			markCompleted(method, argument);
 
 			return result;
 		}
@@ -196,6 +203,27 @@ public class CompletionRegisteringAdvisor extends AbstractPointcutAdvisor {
 			return Ordered.HIGHEST_PRECEDENCE + 10;
 		}
 
+		@Nullable
+		private static Void handleFailure(Method method, Throwable o_O) {
+
+			if (LOG.isDebugEnabled()) {
+				LOG.debug("Invocation of listener {} failed. Leaving event publication uncompleted.", method, o_O);
+			} else {
+				LOG.info("Invocation of listener {} failed with message {}. Leaving event publication uncompleted.",
+						method, o_O.getMessage());
+			}
+
+			return null;
+		}
+
+		private void markCompleted(Method method, Object event) {
+
+			// Mark publication complete if the method is a transactional event listener.
+			String adapterId = ADAPTERS.get(method).getListenerId();
+			PublicationTargetIdentifier identifier = PublicationTargetIdentifier.of(adapterId);
+			registry.get().markCompleted(event, identifier);
+		}
+
 		private static TransactionalApplicationListenerMethodAdapter createAdapter(Method method) {
 			return new TransactionalApplicationListenerMethodAdapter(null, method.getDeclaringClass(), method);
 		}
diff --git a/spring-modulith-events/spring-modulith-events-core/src/test/java/org/springframework/modulith/events/support/CompletionRegisteringAdvisorUnitTests.java b/spring-modulith-events/spring-modulith-events-core/src/test/java/org/springframework/modulith/events/support/CompletionRegisteringAdvisorUnitTests.java
index 9197638a..915b9ebc 100644
--- a/spring-modulith-events/spring-modulith-events-core/src/test/java/org/springframework/modulith/events/support/CompletionRegisteringAdvisorUnitTests.java
+++ b/spring-modulith-events/spring-modulith-events-core/src/test/java/org/springframework/modulith/events/support/CompletionRegisteringAdvisorUnitTests.java
@@ -19,6 +19,7 @@ import static org.assertj.core.api.Assertions.*;
 import static org.mockito.ArgumentMatchers.*;
 import static org.mockito.Mockito.*;
 
+import java.util.concurrent.CompletableFuture;
 import java.util.function.BiConsumer;
 
 import org.junit.jupiter.api.Test;
@@ -26,6 +27,7 @@ import org.springframework.aop.framework.Advised;
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.context.event.EventListener;
 import org.springframework.modulith.events.core.EventPublicationRegistry;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.transaction.event.TransactionPhase;
 import org.springframework.transaction.event.TransactionalEventListener;
 
@@ -59,6 +61,34 @@ class CompletionRegisteringAdvisorUnitTests {
 		assertNonCompletion(SomeEventListener::nonEventListener);
 	}
 
+	@Test // GH-399
+	void doesNotTriggerCompletionOnFailedCompletableFuture() throws Throwable {
+
+		var result = createProxyFor(bean).asyncWithResult(true);
+
+		assertThat(result.isDone()).isFalse();
+		verify(registry, never()).markCompleted(any(), any());
+
+		Thread.sleep(500);
+
+		assertThat(result.isCompletedExceptionally()).isTrue();
+		verify(registry, never()).markCompleted(any(), any());
+	}
+
+	@Test // GH-399
+	void marksLazilyComputedCompletableFutureAsCompleted() throws Throwable {
+
+		var result = createProxyFor(bean).asyncWithResult(false);
+
+		assertThat(result.isDone()).isFalse();
+		verify(registry, never()).markCompleted(any(), any());
+
+		Thread.sleep(500);
+
+		assertThat(result.isCompletedExceptionally()).isFalse();
+		verify(registry).markCompleted(any(), any());
+	}
+
 	private void assertCompletion(BiConsumer<SomeEventListener, Object> consumer) {
 		assertCompletion(consumer, true);
 	}
@@ -78,11 +108,12 @@ class CompletionRegisteringAdvisorUnitTests {
 		verify(registry, times(expected ? 1 : 0)).markCompleted(any(), any());
 	}
 
-	private Object createProxyFor(Object bean) {
+	@SuppressWarnings("unchecked")
+	private <T> T createProxyFor(T bean) {
 
 		ProxyFactory factory = new ProxyFactory(bean);
 		factory.addAdvisor(new CompletionRegisteringAdvisor(() -> registry));
-		return factory.getProxy();
+		return (T) factory.getProxy();
 	}
 
 	static class SomeEventListener {
@@ -97,5 +128,22 @@ class CompletionRegisteringAdvisorUnitTests {
 		void simpleEventListener(Object object) {}
 
 		void nonEventListener(Object object) {}
+
+		@Async
+		@TransactionalEventListener
+		CompletableFuture<?> asyncWithResult(boolean fail) {
+
+			return CompletableFuture.completedFuture(new Object())
+					.thenComposeAsync(it -> {
+
+						try {
+							Thread.sleep(200);
+						} catch (InterruptedException e) {}
+
+						return fail
+								? CompletableFuture.failedFuture(new IllegalArgumentException())
+								: CompletableFuture.completedFuture(it);
+					});
+		}
 	}
 }