diff --git a/WORKSPACE b/WORKSPACE
index 96a6228..67f7e9e 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "56aafc4c0bb1b72fba34f5bdfb29ddb1e1a17801",
+    commit = "4a27255dff75eadc98b86391806be13e030e6ff3",
     #local_path = "/home/<user>/projects/bazlets",
 )
 
diff --git a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/GitRefListener.java b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/GitRefListener.java
index 81559f7..6f53d04 100644
--- a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/GitRefListener.java
+++ b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/GitRefListener.java
@@ -18,10 +18,12 @@
 
 import static com.google.gerrit.extensions.client.DiffPreferencesInfo.Whitespace.IGNORE_NONE;
 
+import com.google.common.base.Predicates;
 import com.google.common.collect.Sets;
 import com.google.gerrit.entities.Account;
 import com.google.gerrit.entities.Change;
 import com.google.gerrit.entities.Project;
+import com.google.gerrit.entities.Project.NameKey;
 import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.exceptions.StorageException;
 import com.google.gerrit.extensions.annotations.Listen;
@@ -32,8 +34,10 @@
 import com.google.gerrit.extensions.common.ChangeInfo;
 import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
 import com.google.gerrit.extensions.restapi.RestApiException;
+import com.google.gerrit.server.ChangeMessagesUtil;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.notedb.ChangeNotes;
 import com.google.gerrit.server.patch.PatchList;
 import com.google.gerrit.server.patch.PatchListCache;
 import com.google.gerrit.server.patch.PatchListKey;
@@ -46,6 +50,7 @@
 import java.util.Set;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -64,6 +69,8 @@
 
   private Provider<CurrentUser> currentUserProvider;
 
+  private ChangeNotes.Factory notesFactory;
+
   @Inject
   public GitRefListener(
       GerritApi api,
@@ -72,7 +79,8 @@
       Accounts accounts,
       ReviewerManager reviewerManager,
       OneOffRequestContext oneOffReqCtx,
-      Provider<CurrentUser> currentUserProvider) {
+      Provider<CurrentUser> currentUserProvider,
+      ChangeNotes.Factory notesFactory) {
     this.api = api;
     this.patchListCache = patchListCache;
     this.repositoryManager = repositoryManager;
@@ -80,6 +88,7 @@
     this.reviewerManager = reviewerManager;
     this.oneOffReqCtx = oneOffReqCtx;
     this.currentUserProvider = currentUserProvider;
+    this.notesFactory = notesFactory;
   }
 
   @Override
@@ -120,11 +129,15 @@
     String projectName = event.getProjectName();
     Repository repository;
     try {
-      repository = repositoryManager.openRepository(Project.NameKey.parse(projectName));
+      NameKey projectNameKey = Project.NameKey.parse(projectName);
+      repository = repositoryManager.openRepository(projectNameKey);
       try {
         String refName = event.getRefName();
-        if (refName.startsWith(RefNames.REFS_CHANGES) && !RefNames.isNoteDbMetaRef(refName)) {
-          processEvent(repository, event);
+        Change.Id changeId = Change.Id.fromRef(refName);
+        if (changeId != null
+            && (!RefNames.isNoteDbMetaRef(refName)
+                || isChangeSetReadyForReview(projectNameKey, changeId, event.getNewObjectId()))) {
+          processEvent(repository, event, changeId);
         }
       } finally {
         repository.close();
@@ -134,15 +147,25 @@
     }
   }
 
-  public void processEvent(Repository repository, Event event) {
-    Change.Id cId = Change.Id.fromRef(event.getRefName());
+  private boolean isChangeSetReadyForReview(
+      NameKey project, Change.Id changeId, String metaObjectId) {
+    ChangeNotes changeNotes = notesFactory.createChecked(project, changeId);
+    return !changeNotes.getChange().isWorkInProgress()
+        && changeNotes.getChangeMessages().stream()
+            .filter(message -> message.getKey().uuid().equals(metaObjectId))
+            .map(message -> message.getTag())
+            .filter(Predicates.notNull())
+            .anyMatch(tag -> tag.contains(ChangeMessagesUtil.TAG_SET_READY));
+  }
+
+  public void processEvent(Repository repository, Event event, Change.Id cId) {
     Changes changes = api.changes();
     // The provider injected by Gerrit is shared with other workers on the
     // same local thread and thus cannot be closed in this event listener.
     try {
       ChangeApi cApi = changes.id(cId.get());
       ChangeInfo change = cApi.get();
-      PatchList patchList = getPatchList(event, change);
+      PatchList patchList = getPatchList(repository, event, change);
       if (patchList != null) {
         PathOwners owners = new PathOwners(accounts, repository, change.branch, patchList);
         Set<Account.Id> allReviewers = Sets.newHashSet();
@@ -160,17 +183,23 @@
     }
   }
 
-  private PatchList getPatchList(Event event, ChangeInfo change) {
+  private PatchList getPatchList(Repository repository, Event event, ChangeInfo change) {
     ObjectId newId = null;
-    if (event.getNewObjectId() != null) {
-      newId = ObjectId.fromString(event.getNewObjectId());
-    }
-
-    PatchListKey plKey = PatchListKey.againstCommit(null, newId, IGNORE_NONE);
+    PatchListKey plKey;
     try {
+      if (RefNames.isNoteDbMetaRef(event.getRefName())) {
+        newId = ObjectId.fromString(change.currentRevision);
+        RevCommit revCommit = repository.parseCommit(newId);
+        plKey = PatchListKey.againstBase(newId, revCommit.getParentCount());
+      } else {
+        if (event.getNewObjectId() != null) {
+          newId = ObjectId.fromString(event.getNewObjectId());
+        }
+        plKey = PatchListKey.againstCommit(null, newId, IGNORE_NONE);
+      }
       return patchListCache.get(plKey, Project.nameKey(change.project));
-    } catch (PatchListNotAvailableException e) {
-      logger.warn("Could not load patch list: {}", plKey, e);
+    } catch (PatchListNotAvailableException | IOException e) {
+      logger.warn("Could not load patch list for change {}", change.id, e);
     }
     return null;
   }
diff --git a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerIT.java b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerIT.java
index 58db2d8..18dea29 100644
--- a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerIT.java
+++ b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerIT.java
@@ -21,11 +21,14 @@
 import com.google.gerrit.acceptance.TestPlugin;
 import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.extensions.registration.Extension;
 import com.google.gerrit.server.AnonymousUser;
 import com.google.gerrit.server.util.ManualRequestContext;
 import com.google.gerrit.server.util.ThreadLocalRequestContext;
 import com.google.inject.AbstractModule;
 import com.google.inject.Inject;
+import java.util.stream.StreamSupport;
 import com.googlesource.gerrit.owners.common.ReviewerManager;
 
 import org.eclipse.jgit.transport.ReceiveCommand.Type;
@@ -36,62 +39,97 @@
     sysModule = "com.googlesource.gerrit.owners.common.GitRefListenerIT$TestModule")
 public class GitRefListenerIT extends LightweightPluginDaemonTest {
 
-  @Inject GitRefListenerTest gitRefListener;
+  @Inject DynamicSet<GitReferenceUpdatedListener> allRefUpdateListeners;
   @Inject ThreadLocalRequestContext requestContext;
 
-  String aRefChange = RefNames.REFS_CHANGES + "01/01/01";
   String anOldObjectId = "anOldRef";
   String aNewObjectId = "aNewRef";
 
   public static class TestModule extends AbstractModule {
     @Override
     protected void configure() {
-      bind(GitReferenceUpdatedListener.class).to(GitRefListenerTest.class);
+      DynamicSet.bind(binder(), GitReferenceUpdatedListener.class).to(GitRefListenerTest.class);
     }
   }
 
   @Test
-  public void shouldNotProcessNoteDbOnlyRefs() {
+  public void shouldNotProcessNoteDbOnlyRefs() throws Exception {
+    String changeRefPrefix = createChange().getChange().getId().toRefPrefix();
+    int baselineProcessedEvents = gitRefListener().getProcessedEvents();
+
     ReferenceUpdatedEventTest refUpdatedEvent =
         new ReferenceUpdatedEventTest(
             project,
-            RefNames.REFS_CHANGES + "01/01" + RefNames.META_SUFFIX,
+            changeRefPrefix + RefNames.META_SUFFIX.substring(1),
             anOldObjectId,
             aNewObjectId,
             Type.CREATE,
             admin.id());
 
-    gitRefListener.onGitReferenceUpdated(refUpdatedEvent);
-    assertEquals(0, gitRefListener.getProcessedEvents());
+    gitRefListener().onGitReferenceUpdated(refUpdatedEvent);
+    assertEquals(baselineProcessedEvents, gitRefListener().getProcessedEvents());
   }
 
   @Test
-  public void shouldProcessRefChanges() {
-    gitRefListener.onGitReferenceUpdated(newRefUpdateEvent());
-    assertEquals(1, gitRefListener.getProcessedEvents());
+  public void shoulProcessSetReadyForReviewOnNoteDb() throws Exception {
+    int wipChangeNum = createChange().getChange().getId().get();
+    gApi.changes().id(wipChangeNum).setWorkInProgress();
+
+    int baselineProcessedEvents = gitRefListener().getProcessedEvents();
+
+    gApi.changes().id(wipChangeNum).setReadyForReview();
+    assertEquals(1, gitRefListener().getProcessedEvents() - baselineProcessedEvents);
+  }
+
+  @Test
+  public void shoulNotProcessEmptyMetaRefUpdatesAfterSetReadyForReviewOnNoteDb() throws Exception {
+    int wipChangeNum = createChange().getChange().getId().get();
+    gApi.changes().id(wipChangeNum).setWorkInProgress();
+    gApi.changes().id(wipChangeNum).setReadyForReview();
+    int baselineProcessedEvents = gitRefListener().getProcessedEvents();
+
+    gApi.changes().id(wipChangeNum).addReviewer("user");
+    assertEquals(baselineProcessedEvents, gitRefListener().getProcessedEvents());
+  }
+
+  @Test
+  public void shouldProcessRefChanges() throws Exception {
+    gitRefListener().onGitReferenceUpdated(newRefUpdateEvent());
+    assertEquals(1, gitRefListener().getProcessedEvents());
   }
 
   @Test
   public void shouldRetrieveChangeFromAnonymousContext() throws Exception {
     try (ManualRequestContext ctx = new ManualRequestContext(new AnonymousUser(), requestContext)) {
-      gitRefListener.onGitReferenceUpdated(newRefUpdateEvent());
-      assertEquals(1, gitRefListener.getProcessedEvents());
+      gitRefListener().onGitReferenceUpdated(newRefUpdateEvent());
+      assertEquals(1, gitRefListener().getProcessedEvents());
     }
   }
 
   @Test
   public void shouldRetrieveChangeFromAnonymousContextWithoutAccountId() throws Exception {
+    String refPrefix = createChange().getChange().getId().toRefPrefix();
     ReferenceUpdatedEventTest refUpdateWithoutAccountId =
         new ReferenceUpdatedEventTest(
-            project, aRefChange, anOldObjectId, aNewObjectId, Type.CREATE, null);
+            project, refPrefix, anOldObjectId, aNewObjectId, Type.CREATE, null);
     try (ManualRequestContext ctx = new ManualRequestContext(new AnonymousUser(), requestContext)) {
-      gitRefListener.onGitReferenceUpdated(refUpdateWithoutAccountId);
-      assertEquals(1, gitRefListener.getProcessedEvents());
+      gitRefListener().onGitReferenceUpdated(refUpdateWithoutAccountId);
+      assertEquals(1, gitRefListener().getProcessedEvents());
     }
   }
 
-  private ReferenceUpdatedEventTest newRefUpdateEvent() {
+  private GitRefListenerTest gitRefListener() {
+    return (GitRefListenerTest)
+        StreamSupport.stream(allRefUpdateListeners.entries().spliterator(), false)
+            .map(Extension::get)
+            .filter(listener -> GitRefListenerTest.class.isAssignableFrom(listener.getClass()))
+            .findFirst()
+            .get();
+  }
+
+  private ReferenceUpdatedEventTest newRefUpdateEvent() throws Exception {
+    String refPrefix = createChange().getChange().getId().toRefPrefix();
     return new ReferenceUpdatedEventTest(
-        project, aRefChange, anOldObjectId, aNewObjectId, Type.CREATE, admin.id());
+        project, refPrefix, anOldObjectId, aNewObjectId, Type.CREATE, admin.id());
   }
 }
diff --git a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerTest.java b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerTest.java
index e862ed9..fef3f29 100644
--- a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerTest.java
+++ b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerTest.java
@@ -15,13 +15,17 @@
 
 package com.googlesource.gerrit.owners.common;
 
+import com.google.gerrit.entities.Change;
 import com.google.gerrit.extensions.api.GerritApi;
+import com.google.gerrit.extensions.events.GitReferenceUpdatedListener.Event;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.notedb.ChangeNotes;
 import com.google.gerrit.server.patch.PatchListCache;
 import com.google.gerrit.server.util.OneOffRequestContext;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 import com.googlesource.gerrit.owners.common.Accounts;
 import com.googlesource.gerrit.owners.common.GitRefListener;
 import com.googlesource.gerrit.owners.common.ReviewerManager;
@@ -29,6 +33,7 @@
 import org.junit.Ignore;
 
 @Ignore
+@Singleton
 public class GitRefListenerTest extends GitRefListener {
   int processedEvents = 0;
 
@@ -40,7 +45,8 @@
       Accounts accounts,
       SyncReviewerManager reviewerManager,
       OneOffRequestContext oneOffReqCtx,
-      Provider<CurrentUser> currentUserProvider) {
+      Provider<CurrentUser> currentUserProvider,
+      ChangeNotes.Factory notesFactory) {
     super(
         api,
         patchListCache,
@@ -48,11 +54,12 @@
         accounts,
         reviewerManager,
         oneOffReqCtx,
-        currentUserProvider);
+        currentUserProvider,
+        notesFactory);
   }
 
   @Override
-  public void processEvent(Repository repository, Event event) {
+  public void processEvent(Repository repository, Event event, Change.Id cId) {
     processedEvents++;
   }