diff --git a/src/main/java/com/googlesource/gerrit/plugins/multisite/Configuration.java b/src/main/java/com/googlesource/gerrit/plugins/multisite/Configuration.java
index 5c443e7..e3f53ab 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/multisite/Configuration.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/multisite/Configuration.java
@@ -306,12 +306,15 @@
     static final String INDEX_SECTION = "index";
     static final String MAX_TRIES_KEY = "maxTries";
     static final String RETRY_INTERVAL_KEY = "retryInterval";
+    static final String SYNCHRONIZE_FORCED_KEY = "synchronizeForced";
+    static final boolean DEFAULT_SYNCHRONIZE_FORCED = true;
 
     private final int threadPoolSize;
     private final int retryInterval;
     private final int maxTries;
 
     private final int numStripedLocks;
+    private final boolean synchronizeForced;
 
     private Index(Supplier<Config> cfg) {
       super(cfg, INDEX_SECTION);
@@ -322,6 +325,8 @@
       maxTries = getInt(cfg, INDEX_SECTION, null, MAX_TRIES_KEY, DEFAULT_INDEX_MAX_TRIES);
       numStripedLocks =
           getInt(cfg, INDEX_SECTION, null, NUM_STRIPED_LOCKS, DEFAULT_NUM_STRIPED_LOCKS);
+      synchronizeForced =
+          getBoolean(cfg, INDEX_SECTION, null, SYNCHRONIZE_FORCED_KEY, DEFAULT_SYNCHRONIZE_FORCED);
     }
 
     public int threadPoolSize() {
@@ -339,6 +344,10 @@
     public int numStripedLocks() {
       return numStripedLocks;
     }
+
+    public boolean synchronizeForced() {
+      return synchronizeForced;
+    }
   }
 
   public static class Broker {
diff --git a/src/main/java/com/googlesource/gerrit/plugins/multisite/index/CurrentRequestContext.java b/src/main/java/com/googlesource/gerrit/plugins/multisite/index/CurrentRequestContext.java
new file mode 100644
index 0000000..d6598b9
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/multisite/index/CurrentRequestContext.java
@@ -0,0 +1,58 @@
+// Copyright (C) 2023 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.multisite.index;
+
+import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.server.util.ManualRequestContext;
+import com.google.gerrit.server.util.OneOffRequestContext;
+import com.google.gerrit.server.util.RequestContext;
+import com.google.gerrit.server.util.ThreadLocalRequestContext;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+import com.googlesource.gerrit.plugins.multisite.Configuration;
+import java.util.function.Consumer;
+
+@Singleton
+public class CurrentRequestContext {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  private ThreadLocalRequestContext threadLocalCtx;
+  private Configuration cfg;
+  private OneOffRequestContext oneOffCtx;
+
+  @Inject
+  public CurrentRequestContext(
+      ThreadLocalRequestContext threadLocalCtx, Configuration cfg, OneOffRequestContext oneOffCtx) {
+    this.threadLocalCtx = threadLocalCtx;
+    this.cfg = cfg;
+    this.oneOffCtx = oneOffCtx;
+  }
+
+  public void onlyWithContext(Consumer<RequestContext> body) {
+    RequestContext ctx = threadLocalCtx.getContext();
+    if (ctx == null && !cfg.index().synchronizeForced()) {
+      logger.atFine().log("No context, skipping event (index.synchronizeForced is false)");
+      return;
+    }
+
+    if (ctx == null) {
+      try (ManualRequestContext manualCtx = oneOffCtx.open()) {
+        body.accept(manualCtx);
+      }
+    } else {
+      body.accept(ctx);
+    }
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/multisite/index/IndexEventHandler.java b/src/main/java/com/googlesource/gerrit/plugins/multisite/index/IndexEventHandler.java
index 4369619..9aee56e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/multisite/index/IndexEventHandler.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/multisite/index/IndexEventHandler.java
@@ -48,6 +48,7 @@
   private final ChangeCheckerImpl.Factory changeChecker;
   private final GroupChecker groupChecker;
   private final String instanceId;
+  private final CurrentRequestContext currCtx;
 
   @Inject
   IndexEventHandler(
@@ -55,27 +56,32 @@
       DynamicSet<IndexEventForwarder> forwarders,
       ChangeCheckerImpl.Factory changeChecker,
       GroupChecker groupChecker,
-      @GerritInstanceId String instanceId) {
+      @GerritInstanceId String instanceId,
+      CurrentRequestContext currCtx) {
     this.forwarders = forwarders;
     this.executor = executor;
     this.changeChecker = changeChecker;
     this.groupChecker = groupChecker;
     this.instanceId = instanceId;
+    this.currCtx = currCtx;
   }
 
   @Override
   public void onAccountIndexed(int id) {
-    if (!Context.isForwardedEvent()) {
-      IndexAccountTask task = new IndexAccountTask(new AccountIndexEvent(id, instanceId));
-      if (queuedTasks.add(task)) {
-        executor.execute(task);
-      }
-    }
+    currCtx.onlyWithContext(
+        (ctx) -> {
+          if (!Context.isForwardedEvent()) {
+            IndexAccountTask task = new IndexAccountTask(new AccountIndexEvent(id, instanceId));
+            if (queuedTasks.add(task)) {
+              executor.execute(task);
+            }
+          }
+        });
   }
 
   @Override
   public void onChangeIndexed(String projectName, int id) {
-    executeIndexChangeTask(projectName, id);
+    currCtx.onlyWithContext((ctx) -> executeIndexChangeTask(projectName, id));
   }
 
   @Override
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index 0cfd6ea..3baa911 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -44,6 +44,11 @@
     service such as ElasticSearch.
     Defaults to true.
 
+```index.synchronizeForced```
+:   Whether to synchronize forced index events. E.g. on-line reindex
+automatically triggered upon version upgrades.
+Defaults to true.
+
 ```index.threadPoolSize```
 :   Maximum number of threads used to send index events to the target instance.
     Defaults to 4.
diff --git a/src/test/java/com/googlesource/gerrit/plugins/multisite/ConfigurationTest.java b/src/test/java/com/googlesource/gerrit/plugins/multisite/ConfigurationTest.java
index 0863f55..3a24773 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/multisite/ConfigurationTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/multisite/ConfigurationTest.java
@@ -21,7 +21,9 @@
 import static com.googlesource.gerrit.plugins.multisite.Configuration.Event.EVENT_SECTION;
 import static com.googlesource.gerrit.plugins.multisite.Configuration.Forwarding.DEFAULT_SYNCHRONIZE;
 import static com.googlesource.gerrit.plugins.multisite.Configuration.Forwarding.SYNCHRONIZE_KEY;
+import static com.googlesource.gerrit.plugins.multisite.Configuration.Index.DEFAULT_SYNCHRONIZE_FORCED;
 import static com.googlesource.gerrit.plugins.multisite.Configuration.Index.INDEX_SECTION;
+import static com.googlesource.gerrit.plugins.multisite.Configuration.Index.SYNCHRONIZE_FORCED_KEY;
 import static com.googlesource.gerrit.plugins.multisite.Configuration.THREAD_POOL_SIZE_KEY;
 
 import com.google.common.collect.ImmutableList;
@@ -129,4 +131,13 @@
     replicationConfig.setBoolean("gerrit", null, "replicateOnStartup", true);
     assertThat(new Configuration(globalPluginConfig, replicationConfig).validate()).isNotEmpty();
   }
+
+  @Test
+  public void testGetIndexSynchronizeForced() throws Exception {
+    assertThat(getConfiguration().index().synchronizeForced())
+        .isEqualTo(DEFAULT_SYNCHRONIZE_FORCED);
+
+    globalPluginConfig.setBoolean(INDEX_SECTION, null, SYNCHRONIZE_FORCED_KEY, false);
+    assertThat(getConfiguration().index().synchronizeForced()).isFalse();
+  }
 }
diff --git a/src/test/java/com/googlesource/gerrit/plugins/multisite/index/IndexEventHandlerTest.java b/src/test/java/com/googlesource/gerrit/plugins/multisite/index/IndexEventHandlerTest.java
index ae5851d..7e27eeb 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/multisite/index/IndexEventHandlerTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/multisite/index/IndexEventHandlerTest.java
@@ -15,14 +15,26 @@
 package com.googlesource.gerrit.plugins.multisite.index;
 
 import static com.googlesource.gerrit.plugins.replication.pull.api.PullReplicationEndpoints.APPLY_OBJECT_API_ENDPOINT;
-import static org.mockito.Mockito.anyString;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.lenient;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
+import static org.mockito.Mockito.when;
 
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.server.util.OneOffRequestContext;
+import com.google.gerrit.server.util.RequestContext;
+import com.google.gerrit.server.util.ThreadLocalRequestContext;
+import com.googlesource.gerrit.plugins.multisite.Configuration;
 import com.googlesource.gerrit.plugins.multisite.forwarder.Context;
 import com.googlesource.gerrit.plugins.multisite.forwarder.IndexEventForwarder;
+import com.googlesource.gerrit.plugins.multisite.forwarder.events.ChangeIndexEvent;
+import java.io.IOException;
+import java.util.Optional;
+import java.util.function.Consumer;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -33,21 +45,34 @@
 public class IndexEventHandlerTest {
 
   private static final String INSTANCE_ID = "instance-id";
+  private static final String PROJECT_NAME = "test_project";
+  private static final int CHANGE_ID = 1;
 
   private IndexEventHandler eventHandler;
 
   @Mock private IndexEventForwarder forwarder;
   @Mock private ChangeCheckerImpl.Factory changeChecker;
+  @Mock private ChangeChecker changeCheckerMock;
+  @Mock private RequestContext mockCtx;
+
+  private CurrentRequestContext currCtx =
+      new CurrentRequestContext(null, null, null) {
+        @Override
+        public void onlyWithContext(Consumer<RequestContext> body) {
+          body.accept(mockCtx);
+        }
+      };
 
   @Before
-  public void setUp() {
+  public void setUp() throws IOException {
     eventHandler =
         new IndexEventHandler(
             MoreExecutors.directExecutor(),
             asDynamicSet(forwarder),
             changeChecker,
             new TestGroupChecker(true),
-            INSTANCE_ID);
+            INSTANCE_ID,
+            currCtx);
   }
 
   private DynamicSet<IndexEventForwarder> asDynamicSet(IndexEventForwarder forwarder) {
@@ -62,17 +87,54 @@
     String currentThreadName = Thread.currentThread().getName();
     try {
       Thread.currentThread().setName("pull-replication~" + APPLY_OBJECT_API_ENDPOINT);
-      int changeId = 1;
       Context.setForwardedEvent(false);
       lenient()
           .when(changeChecker.create(anyString()))
           .thenThrow(
               new IllegalStateException("Change indexing event should have not been triggered"));
 
-      eventHandler.onChangeIndexed("test_project", changeId);
+      eventHandler.onChangeIndexed(PROJECT_NAME, CHANGE_ID);
       verifyNoInteractions(changeChecker);
     } finally {
       Thread.currentThread().setName(currentThreadName);
     }
   }
+
+  @Test
+  public void shouldNotForwardIndexChangeWhenContextIsMissingAndForcedIndexingDisabled()
+      throws Exception {
+    eventHandler = createIndexEventHandler(changeChecker, false);
+    eventHandler.onChangeIndexed(PROJECT_NAME, CHANGE_ID);
+    verifyNoInteractions(changeChecker);
+    verifyNoInteractions(forwarder);
+  }
+
+  @Test
+  public void shouldForwardIndexChangeWhenContextIsMissingAndForcedIndexingEnabled()
+      throws Exception {
+    when(changeChecker.create(any())).thenReturn(changeCheckerMock);
+    when(changeCheckerMock.newIndexEvent(PROJECT_NAME, CHANGE_ID, false))
+        .thenReturn(Optional.of(new ChangeIndexEvent(PROJECT_NAME, CHANGE_ID, false, INSTANCE_ID)));
+    eventHandler = createIndexEventHandler(changeChecker, true);
+    eventHandler.onChangeIndexed(PROJECT_NAME, CHANGE_ID);
+    verify(changeCheckerMock).newIndexEvent(PROJECT_NAME, CHANGE_ID, false);
+    verify(forwarder).index(any(), any());
+  }
+
+  private IndexEventHandler createIndexEventHandler(
+      ChangeCheckerImpl.Factory changeChecker, boolean synchronizeForced) {
+    ThreadLocalRequestContext threadLocalCtxMock = mock(ThreadLocalRequestContext.class);
+    OneOffRequestContext oneOffCtxMock = mock(OneOffRequestContext.class);
+    Configuration cfgMock = mock(Configuration.class);
+    Configuration.Index cfgIndex = mock(Configuration.Index.class);
+    when(cfgMock.index()).thenReturn(cfgIndex);
+    when(cfgIndex.synchronizeForced()).thenReturn(synchronizeForced);
+    return new IndexEventHandler(
+        MoreExecutors.directExecutor(),
+        asDynamicSet(forwarder),
+        changeChecker,
+        new TestGroupChecker(true),
+        INSTANCE_ID,
+        new CurrentRequestContext(threadLocalCtxMock, cfgMock, oneOffCtxMock));
+  }
 }