diff --git a/owners-autoassign/BUILD b/owners-autoassign/BUILD
index 024be42..4aa4cec 100644
--- a/owners-autoassign/BUILD
+++ b/owners-autoassign/BUILD
@@ -15,8 +15,8 @@
     ],
     resources = glob(["src/main/**/*"]),
     deps = [
+        ":owners-api-neverlink",
         "//owners-common",
-        "//plugins/owners-api",
     ],
 )
 
@@ -28,10 +28,16 @@
     visibility = ["//visibility:public"],
     deps = PLUGIN_DEPS_NEVERLINK + [
         "//owners-common",
-        "//plugins/owners-api",
+        ":owners-api-neverlink",
     ],
 )
 
+java_library(
+    name = "owners-api-neverlink",
+    neverlink = 1,
+    exports = ["//plugins/owners-api"],
+)
+
 junit_tests(
     name = "owners_autoassign_tests",
     testonly = 1,
diff --git a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/AutoassignModule.java b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/AutoassignModule.java
index 4ed43b2..931c05a 100644
--- a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/AutoassignModule.java
+++ b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/AutoassignModule.java
@@ -16,14 +16,35 @@
 
 package com.googlesource.gerrit.owners.common;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
+import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.inject.AbstractModule;
+import com.google.inject.Inject;
+import com.google.inject.Scopes;
+import com.googlesource.gerrit.owners.api.OwnersAttentionSet;
 
 public class AutoassignModule extends AbstractModule {
+
+  private final Class<? extends OwnersAttentionSet> ownersAttentionSetImpl;
+
+  @Inject
+  public AutoassignModule() {
+    this(DefaultAddAllOwnersToAttentionSet.class);
+  }
+
+  @VisibleForTesting
+  public AutoassignModule(Class<? extends OwnersAttentionSet> ownersAttentionSetImpl) {
+    this.ownersAttentionSetImpl = ownersAttentionSetImpl;
+  }
+
   @Override
   protected void configure() {
     DynamicSet.bind(binder(), GitReferenceUpdatedListener.class).to(GitRefListener.class);
+    DynamicItem.bind(binder(), OwnersAttentionSet.class)
+        .to(ownersAttentionSetImpl)
+        .in(Scopes.SINGLETON);
     install(new AutoassignConfigModule());
   }
 }
diff --git a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/DefaultAddAllOwnersToAttentionSet.java b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/DefaultAddAllOwnersToAttentionSet.java
new file mode 100644
index 0000000..d53a239
--- /dev/null
+++ b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/DefaultAddAllOwnersToAttentionSet.java
@@ -0,0 +1,29 @@
+// Copyright (C) 2021 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.owners.common;
+
+import com.google.gerrit.entities.Account.Id;
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.googlesource.gerrit.owners.api.OwnersAttentionSet;
+import java.util.Collection;
+
+class DefaultAddAllOwnersToAttentionSet implements OwnersAttentionSet {
+
+  @Override
+  public Collection<Id> addToAttentionSet(ChangeInfo changeInfo, Collection<Id> owners) {
+    return owners;
+  }
+}
diff --git a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/ReviewerManager.java b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/ReviewerManager.java
index ea1975c..489381c 100644
--- a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/ReviewerManager.java
+++ b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/ReviewerManager.java
@@ -21,10 +21,10 @@
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.entities.Project.NameKey;
 import com.google.gerrit.extensions.api.GerritApi;
-import com.google.gerrit.extensions.api.changes.AddReviewerInput;
 import com.google.gerrit.extensions.api.changes.AttentionSetInput;
 import com.google.gerrit.extensions.api.changes.ChangeApi;
 import com.google.gerrit.extensions.api.changes.ReviewInput;
+import com.google.gerrit.extensions.api.changes.ReviewerInput;
 import com.google.gerrit.extensions.client.ReviewerState;
 import com.google.gerrit.extensions.common.ChangeInfo;
 import com.google.gerrit.extensions.registration.DynamicItem;
@@ -58,15 +58,6 @@
   private final IdentifiedUser.GenericFactory userFactory;
   private final ChangeData.Factory changeDataFactory;
   private final PermissionBackend permissionBackend;
-
-  /**
-   * TODO: The optional injection here is needed for keeping backward compatibility with existing
-   * setups that do not have the owners-api.jar configured as Gerrit libModule.
-   *
-   * <p>Once merged to master, the optional injection can go and this can be moved as extra argument
-   * in the constructor.
-   */
-  @Inject(optional = true)
   private DynamicItem<OwnersAttentionSet> ownersForAttentionSet;
 
   private final AutoassignConfig cfg;
@@ -78,12 +69,15 @@
       IdentifiedUser.GenericFactory userFactory,
       ChangeData.Factory changeDataFactory,
       PermissionBackend permissionBackend,
+      DynamicItem<OwnersAttentionSet> ownersForAttentionSet,
+      PermissionBackend permissionBackend,
       AutoassignConfig cfg) {
     this.requestContext = requestContext;
     this.gApi = gApi;
     this.userFactory = userFactory;
     this.changeDataFactory = changeDataFactory;
     this.permissionBackend = permissionBackend;
+    this.ownersForAttentionSet = ownersForAttentionSet;
     this.cfg = cfg;
   }
 
@@ -107,7 +101,7 @@
         Collection<Account.Id> validOwnersForAttentionSet = new ArrayList<>(accountsIds.size());
         for (Account.Id account : accountsIds) {
           if (!currentReviewers.contains(account.get()) && isVisibleTo(changeInfo, account)) {
-            AddReviewerInput addReviewerInput = new AddReviewerInput();
+            ReviewerInput addReviewerInput = new ReviewerInput();
             addReviewerInput.reviewer = account.toString();
             addReviewerInput.state = reviewerState;
             in.reviewers.add(addReviewerInput);
@@ -137,7 +131,7 @@
 
         in.ignoreAutomaticAttentionSetRules = true;
         in.addToAttentionSet =
-            reviewersAccounts.stream()
+            ownersForAttentionSet.get().addToAttentionSet(changeInfo, reviewers).stream()
                 .map(
                     (reviewer) ->
                         new AttentionSetInput(
diff --git a/owners-autoassign/src/main/resources/Documentation/config.md b/owners-autoassign/src/main/resources/Documentation/config.md
index afb534c..96a8fa0 100644
--- a/owners-autoassign/src/main/resources/Documentation/config.md
+++ b/owners-autoassign/src/main/resources/Documentation/config.md
@@ -1,3 +1,13 @@
+## Setup
+
+The owners-autoassign plugin depends on the shared library `owners-api.jar`
+which needs to be installed into the `$GERRIT_SITE/lib` and requires a
+restart of the Gerrit service.
+
+Once the `owners-api.jar` is loaded at Gerrit startup, the `owners-autoassign.jar`
+file can be installed like a regular Gerrit plugin, by being dropped to the
+`GRRIT_SITE/plugins` directory or installed through the plugin manager.
+
 ## Project configuration
 
 The project configuration `autoAssignWip` controls the automatic
diff --git a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/AbstractAutoassignIT.java b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/AbstractAutoassignIT.java
index 4aa6ff4..164d121 100644
--- a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/AbstractAutoassignIT.java
+++ b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/AbstractAutoassignIT.java
@@ -31,6 +31,8 @@
 import com.google.gerrit.server.project.ProjectConfig;
 import com.google.inject.AbstractModule;
 import com.google.inject.Inject;
+import com.google.inject.Module;
+import com.googlesource.gerrit.owners.api.OwnersApiModule;
 import java.util.Collection;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -63,6 +65,11 @@
   }
 
   @Override
+  public Module createModule() {
+    return new OwnersApiModule();
+  }
+
+  @Override
   public void setUpTestPlugin() throws Exception {
     super.setUpTestPlugin();
 
diff --git a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/OwnersAutoassignWithAttentionSetIT.java b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/OwnersAutoassignWithAttentionSetIT.java
index 36795a6..a5c683b 100644
--- a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/OwnersAutoassignWithAttentionSetIT.java
+++ b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/OwnersAutoassignWithAttentionSetIT.java
@@ -30,12 +30,10 @@
 import com.google.gerrit.extensions.api.groups.GroupInput;
 import com.google.gerrit.extensions.client.ReviewerState;
 import com.google.gerrit.extensions.common.ChangeInfo;
-import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.inject.AbstractModule;
 import com.google.inject.Inject;
 import com.google.inject.Module;
-import com.google.inject.Scopes;
 import com.googlesource.gerrit.owners.api.OwnersApiModule;
 import com.googlesource.gerrit.owners.api.OwnersAttentionSet;
 import java.util.Collection;
@@ -58,11 +56,7 @@
   public static class TestModule extends AbstractModule {
     @Override
     protected void configure() {
-      install(new AutoassignModule());
-
-      DynamicItem.bind(binder(), OwnersAttentionSet.class)
-          .to(SelectFirstOwnerForAttentionSet.class)
-          .in(Scopes.SINGLETON);
+      install(new AutoassignModule(SelectFirstOwnerForAttentionSet.class));
     }
   }
 
diff --git a/owners-autoassign/src/test/java/com/vmware/gerrit/owners/common/GitRefListenerIT.java b/owners-autoassign/src/test/java/com/vmware/gerrit/owners/common/GitRefListenerIT.java
index 2cbceda..884c986 100644
--- a/owners-autoassign/src/test/java/com/vmware/gerrit/owners/common/GitRefListenerIT.java
+++ b/owners-autoassign/src/test/java/com/vmware/gerrit/owners/common/GitRefListenerIT.java
@@ -35,6 +35,8 @@
 import com.google.gerrit.server.util.ThreadLocalRequestContext;
 import com.google.inject.AbstractModule;
 import com.google.inject.Inject;
+import com.google.inject.Module;
+import com.googlesource.gerrit.owners.api.OwnersApiModule;
 import com.googlesource.gerrit.owners.common.AutoassignConfigModule;
 import java.util.HashMap;
 import java.util.Map;
@@ -54,6 +56,11 @@
   String anOldObjectId = "anOldRef";
   String aNewObjectId = "aNewRef";
 
+  @Override
+  public Module createModule() {
+    return new OwnersApiModule();
+  }
+
   public static class TestModule extends AbstractModule {
     @Override
     protected void configure() {