diff --git a/hibernate-reactive-core/src/main/java/org/hibernate/reactive/event/impl/AbstractReactiveSaveEventListener.java b/hibernate-reactive-core/src/main/java/org/hibernate/reactive/event/impl/AbstractReactiveSaveEventListener.java
index e9d68b00e..c0ef66b17 100644
--- a/hibernate-reactive-core/src/main/java/org/hibernate/reactive/event/impl/AbstractReactiveSaveEventListener.java
+++ b/hibernate-reactive-core/src/main/java/org/hibernate/reactive/event/impl/AbstractReactiveSaveEventListener.java
@@ -144,55 +144,59 @@ else if ( generator instanceof Assigned ) {
 			// the entity instance, so it will be available
 			// to the entity in the @PrePersist callback
 			if ( generator instanceof ReactiveIdentifierGenerator ) {
-				return ( (ReactiveIdentifierGenerator<?>) generator )
-						.generate( ( ReactiveConnectionSupplier ) source, entity )
-						.thenApply( id -> castToIdentifierType( id, persister ) )
-						.thenCompose( gid -> performSaveWithId(
-								entity,
-								context,
-								source,
-								persister,
-								generator,
-								gid,
-								requiresImmediateIdAccess,
-								false
-						) );
+				return generateId( entity, source, (ReactiveIdentifierGenerator<?>) generator, persister )
+						.thenCompose( gid -> {
+							if ( gid == SHORT_CIRCUIT_INDICATOR ) {
+								source.getIdentifier( entity );
+								return voidFuture();
+							}
+							persister.setIdentifier( entity, gid, source );
+							return reactivePerformSave(
+									entity,
+									gid,
+									persister,
+									generatedOnExecution,
+									context,
+									source,
+									false
+							);
+						} );
 			}
 
 			generatedId = ( (BeforeExecutionGenerator) generator ).generate( source, entity, null, INSERT );
+			if ( generatedId == SHORT_CIRCUIT_INDICATOR ) {
+				source.getIdentifier( entity );
+				return voidFuture();
+			}
+			persister.setIdentifier( entity, generatedId, source );
 		}
 		final Object id =  castToIdentifierType( generatedId, persister );
-		return reactivePerformSave( entity, id, persister, generatedOnExecution, context, source, requiresImmediateIdAccess );
+		final boolean delayIdentityInserts = !source.isTransactionInProgress() && !requiresImmediateIdAccess && generatedOnExecution;
+		return reactivePerformSave( entity, id, persister, generatedOnExecution, context, source, delayIdentityInserts );
 	}
 
-	private CompletionStage<Void> performSaveWithId(
+	private CompletionStage<Object> generateId(
 			Object entity,
-			C context,
 			EventSource source,
-			EntityPersister persister,
-			Generator generator,
-			Object generatedId,
-			boolean requiresImmediateIdAccess,
-			boolean generatedOnExecution) {
-		if ( generatedId == null ) {
-			throw new IdentifierGenerationException( "null id generated for: " + entity.getClass() );
-		}
-		if ( generatedId == SHORT_CIRCUIT_INDICATOR ) {
-			source.getIdentifier( entity );
-			return voidFuture();
-		}
-		if ( LOG.isDebugEnabled() ) {
-			LOG.debugf(
-					"Generated identifier: %s, using strategy: %s",
-					persister.getIdentifierType().toLoggableString( generatedId, source.getFactory() ),
-					generator.getClass().getName()
-			);
-		}
-		final boolean delayIdentityInserts =
-				!source.isTransactionInProgress()
-						&& !requiresImmediateIdAccess
-						&& generatedOnExecution;
-		return reactivePerformSave( entity, generatedId, persister, false, context, source, delayIdentityInserts );
+			ReactiveIdentifierGenerator<?> generator,
+			EntityPersister persister) {
+		return generator
+				.generate( (ReactiveConnectionSupplier) source, entity )
+				.thenApply( id -> {
+								final Object generatedId = castToIdentifierType( id, persister );
+								if ( generatedId == null ) {
+									throw new IdentifierGenerationException( "null id generated for: " + entity.getClass() );
+								}
+								if ( LOG.isDebugEnabled() ) {
+									LOG.debugf(
+											"Generated identifier: %s, using strategy: %s",
+											persister.getIdentifierType().toLoggableString( generatedId, source.getFactory() ),
+											generator.getClass().getName()
+									);
+								}
+								return generatedId;
+							}
+				);
 	}
 
 	/**
@@ -232,10 +236,7 @@ protected CompletionStage<Void> reactivePerformSave(
 		if ( persister.getGenerator() instanceof Assigned ) {
 			id = persister.getIdentifier( entity, source );
 			if ( id == null ) {
-				throw new IdentifierGenerationException(
-						"Identifier of entity '" + persister.getEntityName()
-								+ "' must be manually assigned before calling 'persist()'"
-				);
+				return failedFuture( new IdentifierGenerationException( "Identifier of entity '" + persister.getEntityName() + "' must be manually assigned before calling 'persist()'" ) );
 			}
 		}
 
diff --git a/hibernate-reactive-core/src/test/java/org/hibernate/reactive/OneToOneMapsIdAndGeneratedIdTest.java b/hibernate-reactive-core/src/test/java/org/hibernate/reactive/OneToOneMapsIdAndGeneratedIdTest.java
new file mode 100644
index 000000000..7aca2c611
--- /dev/null
+++ b/hibernate-reactive-core/src/test/java/org/hibernate/reactive/OneToOneMapsIdAndGeneratedIdTest.java
@@ -0,0 +1,154 @@
+/* Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright: Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.reactive;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+
+import org.junit.jupiter.api.Test;
+
+import io.vertx.junit5.Timeout;
+import io.vertx.junit5.VertxTestContext;
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.MapsId;
+import jakarta.persistence.OneToOne;
+
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static org.assertj.core.api.Assertions.assertThat;
+
+@Timeout(value = 10, timeUnit = MINUTES)
+public class OneToOneMapsIdAndGeneratedIdTest extends BaseReactiveTest {
+
+	@Override
+	protected Collection<Class<?>> annotatedEntities() {
+		return List.of( Person.class, NaturalPerson.class );
+	}
+
+	@Test
+	public void testPersist(VertxTestContext context) {
+		NaturalPerson naturalPerson = new NaturalPerson( "natual" );
+		Person person = new Person( "person", naturalPerson );
+
+		test(
+				context, getMutinySessionFactory()
+						.withTransaction( session -> session.persist( person ) )
+						.chain( () -> getMutinySessionFactory()
+								.withTransaction( session -> session
+										.find( Person.class, person.getId() )
+										.invoke( result -> {
+											assertThat( result ).isNotNull();
+											assertThat( result.getNaturalPerson() ).isNotNull();
+											assertThat( result.getNaturalPerson().getId() ).isEqualTo( result.getId() );
+										} ) )
+						)
+		);
+
+	}
+
+	@Entity
+	public static class Person {
+
+		@Id
+		@GeneratedValue(strategy = GenerationType.IDENTITY)
+		private Long id;
+
+		private String name;
+
+		@OneToOne(mappedBy = "person", cascade = CascadeType.ALL)
+		private NaturalPerson naturalPerson;
+
+		public Person() {
+		}
+
+		public Person(String name, NaturalPerson naturalPerson) {
+			this.name = name;
+			this.naturalPerson = naturalPerson;
+			naturalPerson.person = this;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public NaturalPerson getNaturalPerson() {
+			return naturalPerson;
+		}
+
+		@Override
+		public boolean equals(Object o) {
+			if ( o == null || getClass() != o.getClass() ) {
+				return false;
+			}
+			Person person = (Person) o;
+			return Objects.equals( name, person.name );
+		}
+
+		@Override
+		public int hashCode() {
+			return Objects.hashCode( name );
+		}
+	}
+
+	@Entity
+	public static class NaturalPerson {
+
+		@Id
+		private Long id;
+
+		@Column
+		private String name;
+
+		@OneToOne(fetch = FetchType.LAZY)
+		@MapsId
+		private Person person;
+
+		public NaturalPerson() {
+		}
+
+		public NaturalPerson(String name) {
+			this.name = name;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public Person getPerson() {
+			return person;
+		}
+
+		@Override
+		public boolean equals(Object o) {
+			if ( o == null || getClass() != o.getClass() ) {
+				return false;
+			}
+			NaturalPerson that = (NaturalPerson) o;
+			return Objects.equals( name, that.name );
+		}
+
+		@Override
+		public int hashCode() {
+			return Objects.hashCode( name );
+		}
+	}
+
+
+}