diff --git a/Documentation/user-search.txt b/Documentation/user-search.txt
index bf580593a6..c0128c3ce2 100644
--- a/Documentation/user-search.txt
+++ b/Documentation/user-search.txt
@@ -73,6 +73,11 @@ assignee:'USER'::
 +
 Changes assigned to the given user.
 
+[[attention]]
+attention:'USER'::
++
+Changes whose attention set includes the given user.
+
 [[before_until]]
 before:'TIME'/until:'TIME'::
 +
diff --git a/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java b/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
index f659bcaf1a..d3fa8dad4f 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
@@ -405,6 +405,15 @@ class ElasticChangeIndex extends AbstractElasticIndex<Change.Id, ChangeData>
     // Unresolved-comment-count.
     decodeUnresolvedCommentCount(source, ChangeField.UNRESOLVED_COMMENT_COUNT.getName(), cd);
 
+    // Attention set.
+    if (fields.contains(ChangeField.ATTENTION_SET_FULL.getName())) {
+      ChangeField.parseAttentionSet(
+          FluentIterable.from(source.getAsJsonArray(ChangeField.ATTENTION_SET_FULL.getName()))
+              .transform(JsonElement::getAsString)
+              .toSet(),
+          cd);
+    }
+
     return cd;
   }
 
diff --git a/java/com/google/gerrit/index/FieldDef.java b/java/com/google/gerrit/index/FieldDef.java
index fb48104626..63f68879a8 100644
--- a/java/com/google/gerrit/index/FieldDef.java
+++ b/java/com/google/gerrit/index/FieldDef.java
@@ -91,7 +91,9 @@ public final class FieldDef<I, T> {
 
   private final String name;
   private final FieldType<?> type;
+  /** Allow reading the actual data from the index. */
   private final boolean stored;
+
   private final boolean repeatable;
   private final Getter<I, T> getter;
 
diff --git a/java/com/google/gerrit/lucene/LuceneChangeIndex.java b/java/com/google/gerrit/lucene/LuceneChangeIndex.java
index 495c7e5cdb..bf1a16645f 100644
--- a/java/com/google/gerrit/lucene/LuceneChangeIndex.java
+++ b/java/com/google/gerrit/lucene/LuceneChangeIndex.java
@@ -15,6 +15,7 @@
 package com.google.gerrit.lucene;
 
 import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.gerrit.lucene.AbstractLuceneIndex.sortFieldName;
 import static com.google.gerrit.server.git.QueueProvider.QueueType.INTERACTIVE;
 import static com.google.gerrit.server.index.change.ChangeField.LEGACY_ID;
@@ -138,6 +139,7 @@ public class LuceneChangeIndex implements ChangeIndex {
   private static final String TOTAL_COMMENT_COUNT_FIELD = ChangeField.TOTAL_COMMENT_COUNT.getName();
   private static final String UNRESOLVED_COMMENT_COUNT_FIELD =
       ChangeField.UNRESOLVED_COMMENT_COUNT.getName();
+  private static final String ATTENTION_SET_FULL_FIELD = ChangeField.ATTENTION_SET_FULL.getName();
 
   @FunctionalInterface
   static interface IdTerm {
@@ -548,6 +550,9 @@ public class LuceneChangeIndex implements ChangeIndex {
     if (fields.contains(PENDING_REVIEWER_BY_EMAIL_FIELD)) {
       decodePendingReviewersByEmail(doc, cd);
     }
+    if (fields.contains(ATTENTION_SET_FULL_FIELD)) {
+      decodeAttentionSet(doc, cd);
+    }
     decodeSubmitRecords(
         doc, SUBMIT_RECORD_STRICT_FIELD, ChangeField.SUBMIT_RULE_OPTIONS_STRICT, cd);
     decodeSubmitRecords(
@@ -672,6 +677,14 @@ public class LuceneChangeIndex implements ChangeIndex {
                 .transform(IndexableField::stringValue)));
   }
 
+  private void decodeAttentionSet(ListMultimap<String, IndexableField> doc, ChangeData cd) {
+    ChangeField.parseAttentionSet(
+        doc.get(ATTENTION_SET_FULL_FIELD).stream()
+            .map(field -> field.binaryValue().utf8ToString())
+            .collect(toImmutableSet()),
+        cd);
+  }
+
   private void decodeSubmitRecords(
       ListMultimap<String, IndexableField> doc,
       String field,
diff --git a/java/com/google/gerrit/server/change/ChangeJson.java b/java/com/google/gerrit/server/change/ChangeJson.java
index e4148a57ac..b464104f82 100644
--- a/java/com/google/gerrit/server/change/ChangeJson.java
+++ b/java/com/google/gerrit/server/change/ChangeJson.java
@@ -33,6 +33,7 @@ import static com.google.gerrit.extensions.client.ListChangesOption.SKIP_DIFFSTA
 import static com.google.gerrit.extensions.client.ListChangesOption.SUBMITTABLE;
 import static com.google.gerrit.extensions.client.ListChangesOption.TRACKING_IDS;
 import static com.google.gerrit.server.ChangeMessagesUtil.createChangeMessageInfo;
+import static com.google.gerrit.server.util.AttentionSetUtil.additionsOnly;
 import static java.util.stream.Collectors.toList;
 
 import com.google.common.base.Joiner;
@@ -50,7 +51,6 @@ import com.google.gerrit.common.data.SubmitRecord.Status;
 import com.google.gerrit.common.data.SubmitRequirement;
 import com.google.gerrit.common.data.SubmitTypeRecord;
 import com.google.gerrit.entities.Account;
-import com.google.gerrit.entities.AttentionSetUpdate;
 import com.google.gerrit.entities.Change;
 import com.google.gerrit.entities.ChangeMessage;
 import com.google.gerrit.entities.PatchSet;
@@ -510,9 +510,8 @@ public class ChangeJson {
     out.topic = in.getTopic();
     if (!cd.attentionSet().isEmpty()) {
       out.attentionSet =
-          cd.attentionSet().stream()
-              // This filtering should match GetAttentionSet.
-              .filter(a -> a.operation() == AttentionSetUpdate.Operation.ADD)
+          // This filtering should match GetAttentionSet.
+          additionsOnly(cd.attentionSet()).stream()
               .collect(
                   toImmutableMap(
                       a -> a.account().get(),
diff --git a/java/com/google/gerrit/server/index/change/ChangeField.java b/java/com/google/gerrit/server/index/change/ChangeField.java
index ffef684733..c6eb39843f 100644
--- a/java/com/google/gerrit/server/index/change/ChangeField.java
+++ b/java/com/google/gerrit/server/index/change/ChangeField.java
@@ -24,6 +24,7 @@ import static com.google.gerrit.index.FieldDef.integer;
 import static com.google.gerrit.index.FieldDef.prefix;
 import static com.google.gerrit.index.FieldDef.storedOnly;
 import static com.google.gerrit.index.FieldDef.timestamp;
+import static com.google.gerrit.server.util.AttentionSetUtil.additionsOnly;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.stream.Collectors.joining;
 import static java.util.stream.Collectors.toList;
@@ -45,6 +46,8 @@ import com.google.common.primitives.Longs;
 import com.google.gerrit.common.data.SubmitRecord;
 import com.google.gerrit.common.data.SubmitRequirement;
 import com.google.gerrit.entities.Account;
+import com.google.gerrit.entities.AttentionSetUpdate;
+import com.google.gerrit.entities.AttentionSetUpdate.Operation;
 import com.google.gerrit.entities.Change;
 import com.google.gerrit.entities.ChangeMessage;
 import com.google.gerrit.entities.PatchSetApproval;
@@ -74,6 +77,7 @@ import com.google.gerrit.server.query.change.ChangeQueryBuilder;
 import com.google.gerrit.server.query.change.ChangeStatusPredicate;
 import com.google.gson.Gson;
 import java.sql.Timestamp;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
@@ -288,6 +292,45 @@ public class ChangeField {
                       ? cd.change().getCherryPickOf().get()
                       : null);
 
+  /** This class decouples the internal and API types from storage. */
+  private static class StoredAttentionSetEntry {
+    final long timestampMillis;
+    final int userId;
+    final String reason;
+    final Operation operation;
+
+    StoredAttentionSetEntry(AttentionSetUpdate attentionSetUpdate) {
+      timestampMillis = attentionSetUpdate.timestamp().toEpochMilli();
+      userId = attentionSetUpdate.account().get();
+      reason = attentionSetUpdate.reason();
+      operation = attentionSetUpdate.operation();
+    }
+
+    AttentionSetUpdate toAttentionSetUpdate() {
+      return AttentionSetUpdate.createFromRead(
+          Instant.ofEpochMilli(timestampMillis), Account.id(userId), operation, reason);
+    }
+  }
+
+  /**
+   * Users included in the attention set of the change. This omits timestamp, reason and possible
+   * future fields.
+   *
+   * @see #ATTENTION_SET_FULL
+   */
+  public static final FieldDef<ChangeData, Iterable<Integer>> ATTENTION_SET_USERS =
+      integer(ChangeQueryBuilder.FIELD_ATTENTION_SET_USERS)
+          .buildRepeatable(ChangeField::getAttentionSetUserIds);
+
+  /**
+   * The full attention set data including timestamp, reason and possible future fields.
+   *
+   * @see #ATTENTION_SET_USERS
+   */
+  public static final FieldDef<ChangeData, Iterable<byte[]>> ATTENTION_SET_FULL =
+      storedOnly(ChangeQueryBuilder.FIELD_ATTENTION_SET_FULL)
+          .buildRepeatable(ChangeField::storedAttentionSet);
+
   /** The user assigned to the change. */
   public static final FieldDef<ChangeData, Integer> ASSIGNEE =
       integer(ChangeQueryBuilder.FIELD_ASSIGNEE)
@@ -463,6 +506,33 @@ public class ChangeField {
     return ReviewerByEmailSet.fromTable(b.build());
   }
 
+  private static ImmutableSet<Integer> getAttentionSetUserIds(ChangeData changeData) {
+    return additionsOnly(changeData.attentionSet()).stream()
+        .map(update -> update.account().get())
+        .collect(toImmutableSet());
+  }
+
+  private static ImmutableSet<byte[]> storedAttentionSet(ChangeData changeData) {
+    return changeData.attentionSet().stream()
+        .map(StoredAttentionSetEntry::new)
+        .map(storedAttentionSetEntry -> GSON.toJson(storedAttentionSetEntry).getBytes(UTF_8))
+        .collect(toImmutableSet());
+  }
+
+  /**
+   * Deserializes the specified attention set entries from JSON and stores them in the specified
+   * change.
+   */
+  public static void parseAttentionSet(
+      Collection<String> storedAttentionSetEntriesJson, ChangeData changeData) {
+    ImmutableSet<AttentionSetUpdate> attentionSet =
+        storedAttentionSetEntriesJson.stream()
+            .map(
+                entry -> GSON.fromJson(entry, StoredAttentionSetEntry.class).toAttentionSetUpdate())
+            .collect(toImmutableSet());
+    changeData.setAttentionSet(attentionSet);
+  }
+
   /** Commit ID of any patch set on the change, using prefix match. */
   public static final FieldDef<ChangeData, Iterable<String>> COMMIT =
       prefix(ChangeQueryBuilder.FIELD_COMMIT).buildRepeatable(ChangeField::getRevisions);
diff --git a/java/com/google/gerrit/server/index/change/ChangeSchemaDefinitions.java b/java/com/google/gerrit/server/index/change/ChangeSchemaDefinitions.java
index 6d6d4b8c37..b232d3979a 100644
--- a/java/com/google/gerrit/server/index/change/ChangeSchemaDefinitions.java
+++ b/java/com/google/gerrit/server/index/change/ChangeSchemaDefinitions.java
@@ -85,12 +85,17 @@ public class ChangeSchemaDefinitions extends SchemaDefinitions<ChangeData> {
           ChangeField.UPDATED,
           ChangeField.WIP);
 
-  // The computation of the 'extension' field is changed, hence reindexing is required.
+  /**
+   * The computation of the {@link ChangeField#EXTENSION} field is changed, hence reindexing is
+   * required.
+   */
   @Deprecated static final Schema<ChangeData> V56 = schema(V55);
 
-  // New numeric types: use dimensional points using the k-d tree geo-spatial data structure
-  // to offer fast single- and multi-dimensional numeric range. As the consequense, integer
-  // document id type is replaced with string document id type.
+  /**
+   * New numeric types: use dimensional points using the k-d tree geo-spatial data structure to
+   * offer fast single- and multi-dimensional numeric range. As the consequense, {@link
+   * ChangeField#LEGACY_ID} is replaced with {@link ChangeField#LEGACY_ID_STR}.
+   */
   @Deprecated
   static final Schema<ChangeData> V57 =
       new Schema.Builder<ChangeData>()
@@ -100,7 +105,11 @@ public class ChangeSchemaDefinitions extends SchemaDefinitions<ChangeData> {
           .legacyNumericFields(false)
           .build();
 
-  // Add new field CHERRY_PICK_OF
+  /**
+   * Added new fields {@link ChangeField#CHERRY_PICK_OF_CHANGE} and {@link
+   * ChangeField#CHERRY_PICK_OF_PATCHSET}.
+   */
+  @Deprecated
   static final Schema<ChangeData> V58 =
       new Schema.Builder<ChangeData>()
           .add(V57)
@@ -108,6 +117,17 @@ public class ChangeSchemaDefinitions extends SchemaDefinitions<ChangeData> {
           .add(ChangeField.CHERRY_PICK_OF_PATCHSET)
           .build();
 
+  /**
+   * Added new fields {@link ChangeField#ATTENTION_SET_USERS} and {@link
+   * ChangeField#ATTENTION_SET_FULL}.
+   */
+  static final Schema<ChangeData> V59 =
+      new Schema.Builder<ChangeData>()
+          .add(V58)
+          .add(ChangeField.ATTENTION_SET_USERS)
+          .add(ChangeField.ATTENTION_SET_FULL)
+          .build();
+
   /**
    * Name of the change index to be used when contacting index backends or loading configurations.
    */
diff --git a/java/com/google/gerrit/server/query/change/AttentionSetPredicate.java b/java/com/google/gerrit/server/query/change/AttentionSetPredicate.java
new file mode 100644
index 0000000000..2b18767a7a
--- /dev/null
+++ b/java/com/google/gerrit/server/query/change/AttentionSetPredicate.java
@@ -0,0 +1,41 @@
+// Copyright (C) 2020 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.google.gerrit.server.query.change;
+
+import static com.google.gerrit.server.util.AttentionSetUtil.additionsOnly;
+
+import com.google.gerrit.entities.Account;
+import com.google.gerrit.server.index.change.ChangeField;
+
+/** Simple predicate for searching by attention set. */
+public class AttentionSetPredicate extends ChangeIndexPredicate {
+  protected final Account.Id id;
+
+  AttentionSetPredicate(Account.Id id) {
+    super(ChangeField.ATTENTION_SET_USERS, id.toString());
+    this.id = id;
+  }
+
+  @Override
+  public boolean match(ChangeData changeData) {
+    return additionsOnly(changeData.attentionSet()).stream()
+        .anyMatch(update -> update.account().equals(id));
+  }
+
+  @Override
+  public int getCost() {
+    return 1;
+  }
+}
diff --git a/java/com/google/gerrit/server/query/change/ChangeData.java b/java/com/google/gerrit/server/query/change/ChangeData.java
index 0b54335c78..6e55bf2552 100644
--- a/java/com/google/gerrit/server/query/change/ChangeData.java
+++ b/java/com/google/gerrit/server/query/change/ChangeData.java
@@ -611,6 +611,21 @@ public class ChangeData {
     return attentionSet;
   }
 
+  /**
+   * Sets the specified attention set. If two or more entries refer to the same user, throws an
+   * {@link IllegalStateException}.
+   */
+  public void setAttentionSet(ImmutableSet<AttentionSetUpdate> attentionSet) {
+    if (attentionSet.stream().map(AttentionSetUpdate::account).distinct().count()
+        != attentionSet.size()) {
+      throw new IllegalStateException(
+          String.format(
+              "Stored attention set for change %d contains duplicate update",
+              change.getId().get()));
+    }
+    this.attentionSet = attentionSet;
+  }
+
   /** @return patches for the change, in patch set ID order. */
   public Collection<PatchSet> patchSets() {
     if (patchSets == null) {
diff --git a/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java b/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java
index edd5411215..f5cb458e4c 100644
--- a/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java
+++ b/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.server.query.change;
 
+import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.gerrit.entities.Change.CHANGE_ID_PATTERN;
 import static com.google.gerrit.server.account.AccountResolver.isSelf;
 import static com.google.gerrit.server.query.change.ChangeData.asChanges;
@@ -136,6 +137,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData, ChangeQueryBuil
 
   public static final String FIELD_ADDED = "added";
   public static final String FIELD_AGE = "age";
+  public static final String FIELD_ATTENTION_SET_USERS = "attentionusers";
+  public static final String FIELD_ATTENTION_SET_FULL = "attentionfull";
   public static final String FIELD_ASSIGNEE = "assignee";
   public static final String FIELD_AUTHOR = "author";
   public static final String FIELD_EXACTAUTHOR = "exactauthor";
@@ -1056,6 +1059,20 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData, ChangeQueryBuil
     return owner(accounts);
   }
 
+  @Operator
+  public Predicate<ChangeData> attention(String who)
+      throws QueryParseException, IOException, ConfigInvalidException {
+    if (!args.index.getSchema().hasField(ChangeField.ATTENTION_SET_USERS)) {
+      throw new QueryParseException(
+          "'attention' operator is not supported by change index version");
+    }
+    return attention(parseAccount(who, (AccountState s) -> true));
+  }
+
+  private Predicate<ChangeData> attention(Set<Account.Id> who) {
+    return Predicate.or(who.stream().map(AttentionSetPredicate::new).collect(toImmutableSet()));
+  }
+
   @Operator
   public Predicate<ChangeData> assignee(String who)
       throws QueryParseException, IOException, ConfigInvalidException {
diff --git a/java/com/google/gerrit/server/restapi/change/GetAttentionSet.java b/java/com/google/gerrit/server/restapi/change/GetAttentionSet.java
index b0dcf8bf5e..08a963bc43 100644
--- a/java/com/google/gerrit/server/restapi/change/GetAttentionSet.java
+++ b/java/com/google/gerrit/server/restapi/change/GetAttentionSet.java
@@ -15,9 +15,9 @@
 package com.google.gerrit.server.restapi.change;
 
 import static com.google.common.collect.ImmutableSet.toImmutableSet;
+import static com.google.gerrit.server.util.AttentionSetUtil.additionsOnly;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.gerrit.entities.AttentionSetUpdate.Operation;
 import com.google.gerrit.extensions.common.AttentionSetEntry;
 import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestReadView;
@@ -45,9 +45,8 @@ public class GetAttentionSet implements RestReadView<ChangeResource> {
       throws PermissionBackendException {
     AccountLoader accountLoader = accountLoaderFactory.create(true);
     ImmutableSet<AttentionSetEntry> response =
-        changeResource.getNotes().getAttentionSet().stream()
-            // This filtering should match ChangeJson.
-            .filter(a -> a.operation() == Operation.ADD)
+        // This filtering should match ChangeJson.
+        additionsOnly(changeResource.getNotes().getAttentionSet()).stream()
             .map(
                 a ->
                     new AttentionSetEntry(
diff --git a/java/com/google/gerrit/server/util/AttentionSetUtil.java b/java/com/google/gerrit/server/util/AttentionSetUtil.java
new file mode 100644
index 0000000000..1cd398fe7d
--- /dev/null
+++ b/java/com/google/gerrit/server/util/AttentionSetUtil.java
@@ -0,0 +1,19 @@
+package com.google.gerrit.server.util;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.gerrit.entities.AttentionSetUpdate;
+import com.google.gerrit.entities.AttentionSetUpdate.Operation;
+import java.util.Collection;
+
+/** Common helpers for dealing with attention set data structures. */
+public class AttentionSetUtil {
+  /** Returns only updates where the user was added. */
+  public static ImmutableSet<AttentionSetUpdate> additionsOnly(
+      Collection<AttentionSetUpdate> updates) {
+    return updates.stream()
+        .filter(u -> u.operation() == Operation.ADD)
+        .collect(ImmutableSet.toImmutableSet());
+  }
+
+  private AttentionSetUtil() {}
+}
diff --git a/javatests/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java b/javatests/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
index 040e2ebfb0..29b9f4f5c3 100644
--- a/javatests/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
+++ b/javatests/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
@@ -54,6 +54,7 @@ import com.google.gerrit.entities.Project;
 import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.extensions.api.GerritApi;
 import com.google.gerrit.extensions.api.changes.AddReviewerInput;
+import com.google.gerrit.extensions.api.changes.AddToAttentionSetInput;
 import com.google.gerrit.extensions.api.changes.AssigneeInput;
 import com.google.gerrit.extensions.api.changes.ChangeApi;
 import com.google.gerrit.extensions.api.changes.Changes.QueryRequest;
@@ -2940,6 +2941,41 @@ public abstract class AbstractQueryChangesTest extends GerritServerTests {
         mergedOwned);
   }
 
+  @Test
+  public void attentionSetIndexed() throws Exception {
+    assume().that(getSchema().hasField(ChangeField.ATTENTION_SET_USERS)).isTrue();
+    TestRepository<Repo> repo = createProject("repo");
+    Change change1 = insert(repo, newChange(repo));
+    Change change2 = insert(repo, newChange(repo));
+
+    AddToAttentionSetInput input = new AddToAttentionSetInput(userId.toString(), "some reason");
+    gApi.changes().id(change1.getChangeId()).addToAttentionSet(input);
+
+    assertQuery("attention:" + user.getUserName().get(), change1);
+    assertQuery("-attention:" + userId.toString(), change2);
+  }
+
+  @Test
+  public void attentionSetStored() throws Exception {
+    assume().that(getSchema().hasField(ChangeField.ATTENTION_SET_USERS)).isTrue();
+    TestRepository<Repo> repo = createProject("repo");
+    Change change = insert(repo, newChange(repo));
+
+    AddToAttentionSetInput input = new AddToAttentionSetInput(userId.toString(), "reason 1");
+    gApi.changes().id(change.getChangeId()).addToAttentionSet(input);
+    Account.Id user2Id =
+        accountManager.authenticate(AuthRequest.forUser("anotheruser")).getAccountId();
+    input = new AddToAttentionSetInput(user2Id.toString(), "reason 2");
+    gApi.changes().id(change.getChangeId()).addToAttentionSet(input);
+
+    List<ChangeInfo> result = newQuery("attention:" + user2Id.toString()).get();
+    assertThat(result).hasSize(1);
+    ChangeInfo changeInfo = Iterables.getOnlyElement(result);
+    assertThat(changeInfo.attentionSet.keySet()).containsExactly(userId.get(), user2Id.get());
+    assertThat(changeInfo.attentionSet.get(userId.get()).reason).isEqualTo("reason 1");
+    assertThat(changeInfo.attentionSet.get(user2Id.get()).reason).isEqualTo("reason 2");
+  }
+
   @Test
   public void assignee() throws Exception {
     TestRepository<Repo> repo = createProject("repo");