diff --git a/java/com/google/gerrit/server/events/EventBroker.java b/java/com/google/gerrit/server/events/EventBroker.java
index 728dd01e21..0fcb64e1ba 100644
--- a/java/com/google/gerrit/server/events/EventBroker.java
+++ b/java/com/google/gerrit/server/events/EventBroker.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.server.events;
 
+import com.google.common.base.Strings;
 import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.entities.BranchNameKey;
@@ -111,7 +112,7 @@ public class EventBroker implements EventDispatcher {
   }
 
   protected void fireEvent(Change change, ChangeEvent event) throws PermissionBackendException {
-    setInstanceId(event);
+    setInstanceIdWhenEmpty(event);
     for (PluginSetEntryContext<UserScopedEventListener> c : listeners) {
       CurrentUser user = c.call(UserScopedEventListener::getUser);
       if (isVisibleTo(change, user)) {
@@ -122,7 +123,7 @@ public class EventBroker implements EventDispatcher {
   }
 
   protected void fireEvent(Project.NameKey project, ProjectEvent event) {
-    setInstanceId(event);
+    setInstanceIdWhenEmpty(event);
     for (PluginSetEntryContext<UserScopedEventListener> c : listeners) {
 
       CurrentUser user = c.call(UserScopedEventListener::getUser);
@@ -135,7 +136,7 @@ public class EventBroker implements EventDispatcher {
 
   protected void fireEvent(BranchNameKey branchName, RefEvent event)
       throws PermissionBackendException {
-    setInstanceId(event);
+    setInstanceIdWhenEmpty(event);
     for (PluginSetEntryContext<UserScopedEventListener> c : listeners) {
       CurrentUser user = c.call(UserScopedEventListener::getUser);
       if (isVisibleTo(branchName, user)) {
@@ -146,7 +147,7 @@ public class EventBroker implements EventDispatcher {
   }
 
   protected void fireEvent(Event event) throws PermissionBackendException {
-    setInstanceId(event);
+    setInstanceIdWhenEmpty(event);
     for (PluginSetEntryContext<UserScopedEventListener> c : listeners) {
       CurrentUser user = c.call(UserScopedEventListener::getUser);
       if (isVisibleTo(event, user)) {
@@ -156,8 +157,10 @@ public class EventBroker implements EventDispatcher {
     fireEventForUnrestrictedListeners(event);
   }
 
-  protected void setInstanceId(Event event) {
-    event.instanceId = gerritInstanceId;
+  protected void setInstanceIdWhenEmpty(Event event) {
+    if (Strings.isNullOrEmpty(event.instanceId)) {
+      event.instanceId = gerritInstanceId;
+    }
   }
 
   protected boolean isVisibleTo(Project.NameKey project, CurrentUser user) {
diff --git a/javatests/com/google/gerrit/acceptance/config/InstanceIdFromPluginIT.java b/javatests/com/google/gerrit/acceptance/config/InstanceIdFromPluginIT.java
index 0956de45c3..ac10e96a29 100644
--- a/javatests/com/google/gerrit/acceptance/config/InstanceIdFromPluginIT.java
+++ b/javatests/com/google/gerrit/acceptance/config/InstanceIdFromPluginIT.java
@@ -19,10 +19,19 @@ import static com.google.common.truth.Truth.assertThat;
 import com.google.gerrit.acceptance.LightweightPluginDaemonTest;
 import com.google.gerrit.acceptance.TestPlugin;
 import com.google.gerrit.common.Nullable;
+import com.google.gerrit.extensions.registration.DynamicItem;
+import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.server.config.GerritInstanceId;
+import com.google.gerrit.server.events.Event;
+import com.google.gerrit.server.events.EventDispatcher;
+import com.google.gerrit.server.events.EventListener;
+import com.google.gerrit.server.permissions.PermissionBackendException;
 import com.google.inject.AbstractModule;
 import com.google.inject.Inject;
+import com.google.inject.Key;
 import com.google.inject.Scopes;
+import java.util.ArrayList;
+import java.util.List;
 import org.junit.Test;
 
 @TestPlugin(
@@ -35,6 +44,8 @@ public class InstanceIdFromPluginIT extends LightweightPluginDaemonTest {
     @Override
     protected void configure() {
       bind(InstanceIdLoader.class).in(Scopes.SINGLETON);
+      bind(TestEventListener.class).in(Scopes.SINGLETON);
+      DynamicSet.bind(binder(), EventListener.class).to(TestEventListener.class);
     }
   }
 
@@ -47,6 +58,27 @@ public class InstanceIdFromPluginIT extends LightweightPluginDaemonTest {
     }
   }
 
+  public static class TestEventListener implements EventListener {
+    private final List<Event> events = new ArrayList<>();
+
+    @Override
+    public void onEvent(Event event) {
+      events.add(event);
+    }
+
+    public List<Event> getEvents() {
+      return events;
+    }
+  }
+
+  public static class TestEvent extends Event {
+
+    protected TestEvent(String instanceId) {
+      super("test");
+      this.instanceId = instanceId;
+    }
+  }
+
   @Test
   @GerritConfig(name = "gerrit.instanceId", value = "testInstanceId")
   public void shouldReturnInstanceIdWhenDefined() {
@@ -58,6 +90,21 @@ public class InstanceIdFromPluginIT extends LightweightPluginDaemonTest {
     assertThat(getInstanceIdLoader().gerritInstanceId).isNull();
   }
 
+  @Test
+  @GerritConfig(name = "gerrit.instanceId", value = "testInstanceId")
+  public void shouldPreserveEventInstanceIdWhenDefined() throws PermissionBackendException {
+    EventDispatcher dispatcher =
+        plugin.getSysInjector().getInstance(new Key<DynamicItem<EventDispatcher>>() {}).get();
+    String eventInstanceId = "eventInstanceId";
+    TestEventListener eventListener = plugin.getSysInjector().getInstance(TestEventListener.class);
+    TestEvent testEvent = new TestEvent(eventInstanceId);
+
+    dispatcher.postEvent(testEvent);
+    List<Event> receivedEvents = eventListener.getEvents();
+    assertThat(receivedEvents).hasSize(1);
+    assertThat(receivedEvents.get(0).instanceId).isEqualTo(eventInstanceId);
+  }
+
   private InstanceIdLoader getInstanceIdLoader() {
     return plugin.getSysInjector().getInstance(InstanceIdLoader.class);
   }