diff --git a/java/com/google/gerrit/server/git/NotifyConfig.java b/java/com/google/gerrit/server/git/NotifyConfig.java
index 429f15a..1a1bbb6 100644
--- a/java/com/google/gerrit/server/git/NotifyConfig.java
+++ b/java/com/google/gerrit/server/git/NotifyConfig.java
@@ -14,113 +14,101 @@
 
 package com.google.gerrit.server.git;
 
-import com.google.common.base.MoreObjects;
+import com.google.auto.value.AutoValue;
 import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.common.data.GroupReference;
 import com.google.gerrit.mail.Address;
 import com.google.gerrit.server.account.ProjectWatches.NotifyType;
 import java.util.EnumSet;
-import java.util.HashSet;
 import java.util.Set;
+import org.eclipse.jgit.annotations.Nullable;
 
-public class NotifyConfig implements Comparable<NotifyConfig> {
+@AutoValue
+public abstract class NotifyConfig implements Comparable<NotifyConfig> {
   public enum Header {
     TO,
     CC,
     BCC
   }
 
-  private String name;
-  private EnumSet<NotifyType> types = EnumSet.of(NotifyType.ALL);
-  private String filter;
+  @Nullable
+  public abstract String getName();
 
-  private Header header;
-  private Set<GroupReference> groups = new HashSet<>();
-  private Set<Address> addresses = new HashSet<>();
+  public abstract ImmutableSet<NotifyType> getNotify();
 
-  public String getName() {
-    return name;
-  }
+  @Nullable
+  public abstract String getFilter();
 
-  public void setName(String name) {
-    this.name = name;
-  }
+  @Nullable
+  public abstract Header getHeader();
+
+  public abstract ImmutableSet<GroupReference> getGroups();
+
+  public abstract ImmutableSet<Address> getAddresses();
 
   public boolean isNotify(NotifyType type) {
-    return types.contains(type) || types.contains(NotifyType.ALL);
+    return getNotify().contains(type) || getNotify().contains(NotifyType.ALL);
   }
 
-  public Set<NotifyType> getNotify() {
-    return types;
+  public static Builder builder() {
+    return new AutoValue_NotifyConfig.Builder()
+        .setNotify(ImmutableSet.copyOf(EnumSet.of(NotifyType.ALL)));
   }
 
-  public void setTypes(Set<NotifyType> newTypes) {
-    types = EnumSet.copyOf(newTypes);
-  }
+  @AutoValue.Builder
+  public abstract static class Builder {
+    public abstract Builder setName(String name);
 
-  public String getFilter() {
-    return filter;
-  }
+    public abstract Builder setNotify(Set<NotifyType> newTypes);
 
-  public void setFilter(String filter) {
-    if ("*".equals(filter)) {
-      this.filter = null;
-    } else {
-      this.filter = Strings.emptyToNull(filter);
+    public abstract Builder setFilter(@Nullable String filter);
+
+    public abstract Builder setHeader(Header hdr);
+
+    public Builder addGroup(GroupReference group) {
+      groupsBuilder().add(group);
+      return this;
+    }
+
+    public Builder addAddress(Address address) {
+      addressesBuilder().add(address);
+      return this;
+    }
+
+    protected abstract ImmutableSet.Builder<GroupReference> groupsBuilder();
+
+    protected abstract ImmutableSet.Builder<Address> addressesBuilder();
+
+    protected abstract NotifyConfig autoBuild();
+
+    protected abstract String getFilter();
+
+    public NotifyConfig build() {
+      if ("*".equals(getFilter())) {
+        setFilter(null);
+      } else {
+        setFilter(Strings.emptyToNull(getFilter()));
+      }
+      return autoBuild();
     }
   }
 
-  public Header getHeader() {
-    return header;
-  }
-
-  public void setHeader(Header hdr) {
-    header = hdr;
-  }
-
-  public Set<GroupReference> getGroups() {
-    return groups;
-  }
-
-  public Set<Address> getAddresses() {
-    return addresses;
-  }
-
-  public void addEmail(GroupReference group) {
-    groups.add(group);
-  }
-
-  public void addEmail(Address address) {
-    addresses.add(address);
+  @Override
+  public final int compareTo(NotifyConfig o) {
+    return getName().compareTo(o.getName());
   }
 
   @Override
-  public int compareTo(NotifyConfig o) {
-    return name.compareTo(o.name);
+  public final int hashCode() {
+    return getName().hashCode();
   }
 
   @Override
-  public int hashCode() {
-    return name.hashCode();
-  }
-
-  @Override
-  public boolean equals(Object obj) {
+  public final boolean equals(Object obj) {
     if (obj instanceof NotifyConfig) {
       return compareTo((NotifyConfig) obj) == 0;
     }
     return false;
   }
-
-  @Override
-  public String toString() {
-    return MoreObjects.toStringHelper(this)
-        .add("name", name)
-        .add("addresses", addresses)
-        .add("groups", groups)
-        .add("header", header)
-        .add("types", types)
-        .add("filter", filter)
-        .toString();
-  }
 }
diff --git a/java/com/google/gerrit/server/project/ProjectConfig.java b/java/com/google/gerrit/server/project/ProjectConfig.java
index 3d4b024..35257ef 100644
--- a/java/com/google/gerrit/server/project/ProjectConfig.java
+++ b/java/com/google/gerrit/server/project/ProjectConfig.java
@@ -741,13 +741,13 @@
   private void loadNotifySections(Config rc) {
     notifySections = new HashMap<>();
     for (String sectionName : rc.getSubsections(NOTIFY)) {
-      NotifyConfig n = new NotifyConfig();
+      NotifyConfig.Builder n = NotifyConfig.builder();
       n.setName(sectionName);
       n.setFilter(rc.getString(NOTIFY, sectionName, KEY_FILTER));
 
       EnumSet<NotifyType> types = EnumSet.noneOf(NotifyType.class);
       types.addAll(ConfigUtil.getEnumList(rc, NOTIFY, sectionName, KEY_TYPE, NotifyType.ALL));
-      n.setTypes(types);
+      n.setNotify(types);
       n.setHeader(rc.getEnum(NOTIFY, sectionName, KEY_HEADER, NotifyConfig.Header.BCC));
 
       for (String dst : rc.getStringList(NOTIFY, sectionName, KEY_EMAIL)) {
@@ -758,7 +758,7 @@
             ref = groupList.resolve(GroupReference.create(groupName));
           }
           if (ref.getUUID() != null) {
-            n.addEmail(ref);
+            n.addGroup(ref);
           } else {
             error(
                 ValidationError.create(
@@ -769,7 +769,7 @@
           error(ValidationError.create(PROJECT_CONFIG, dst + " not supported"));
         } else {
           try {
-            n.addEmail(Address.parse(dst));
+            n.addAddress(Address.parse(dst));
           } catch (IllegalArgumentException err) {
             error(
                 ValidationError.create(
@@ -778,7 +778,7 @@
           }
         }
       }
-      notifySections.put(sectionName, n);
+      notifySections.put(sectionName, n.build());
     }
   }
 
diff --git a/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java b/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
index 7a80cbd..fcdea16 100644
--- a/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
+++ b/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
@@ -50,15 +50,15 @@
   @Test
   public void newPatchSetsNotifyConfig() throws Exception {
     Address addr = Address.create("Watcher", "watcher@example.com");
-    NotifyConfig nc = new NotifyConfig();
-    nc.addEmail(addr);
+    NotifyConfig.Builder nc = NotifyConfig.builder();
+    nc.addAddress(addr);
     nc.setName("new-patch-set");
     nc.setHeader(NotifyConfig.Header.CC);
-    nc.setTypes(EnumSet.of(NotifyType.NEW_PATCHSETS));
+    nc.setNotify(EnumSet.of(NotifyType.NEW_PATCHSETS));
     nc.setFilter("message:sekret");
 
     try (ProjectConfigUpdate u = updateProject(project)) {
-      u.getConfig().putNotifyConfig("watch", nc);
+      u.getConfig().putNotifyConfig("watch", nc.build());
       u.save();
     }
 
@@ -91,14 +91,14 @@
   @Test
   public void noNotificationForPrivateChangesForWatchersInNotifyConfig() throws Exception {
     Address addr = Address.create("Watcher", "watcher@example.com");
-    NotifyConfig nc = new NotifyConfig();
-    nc.addEmail(addr);
+    NotifyConfig.Builder nc = NotifyConfig.builder();
+    nc.addAddress(addr);
     nc.setName("team");
     nc.setHeader(NotifyConfig.Header.TO);
-    nc.setTypes(EnumSet.of(NotifyType.NEW_CHANGES, NotifyType.ALL_COMMENTS));
+    nc.setNotify(EnumSet.of(NotifyType.NEW_CHANGES, NotifyType.ALL_COMMENTS));
 
     try (ProjectConfigUpdate u = updateProject(project)) {
-      u.getConfig().putNotifyConfig("team", nc);
+      u.getConfig().putNotifyConfig("team", nc.build());
       u.save();
     }
 
@@ -123,14 +123,14 @@
   public void noNotificationForChangeThatIsTurnedPrivateForWatchersInNotifyConfig()
       throws Exception {
     Address addr = Address.create("Watcher", "watcher@example.com");
-    NotifyConfig nc = new NotifyConfig();
-    nc.addEmail(addr);
+    NotifyConfig.Builder nc = NotifyConfig.builder();
+    nc.addAddress(addr);
     nc.setName("team");
     nc.setHeader(NotifyConfig.Header.TO);
-    nc.setTypes(EnumSet.of(NotifyType.NEW_PATCHSETS));
+    nc.setNotify(EnumSet.of(NotifyType.NEW_PATCHSETS));
 
     try (ProjectConfigUpdate u = updateProject(project)) {
-      u.getConfig().putNotifyConfig("team", nc);
+      u.getConfig().putNotifyConfig("team", nc.build());
       u.save();
     }
 
@@ -152,14 +152,14 @@
   @Test
   public void noNotificationForWipChangesForWatchersInNotifyConfig() throws Exception {
     Address addr = Address.create("Watcher", "watcher@example.com");
-    NotifyConfig nc = new NotifyConfig();
-    nc.addEmail(addr);
+    NotifyConfig.Builder nc = NotifyConfig.builder();
+    nc.addAddress(addr);
     nc.setName("team");
     nc.setHeader(NotifyConfig.Header.TO);
-    nc.setTypes(EnumSet.of(NotifyType.NEW_CHANGES, NotifyType.ALL_COMMENTS));
+    nc.setNotify(EnumSet.of(NotifyType.NEW_CHANGES, NotifyType.ALL_COMMENTS));
 
     try (ProjectConfigUpdate u = updateProject(project)) {
-      u.getConfig().putNotifyConfig("team", nc);
+      u.getConfig().putNotifyConfig("team", nc.build());
       u.save();
     }
 
@@ -183,14 +183,14 @@
   @Test
   public void noNotificationForChangeThatIsTurnedWipForWatchersInNotifyConfig() throws Exception {
     Address addr = Address.create("Watcher", "watcher@example.com");
-    NotifyConfig nc = new NotifyConfig();
-    nc.addEmail(addr);
+    NotifyConfig.Builder nc = NotifyConfig.builder();
+    nc.addAddress(addr);
     nc.setName("team");
     nc.setHeader(NotifyConfig.Header.TO);
-    nc.setTypes(EnumSet.of(NotifyType.NEW_PATCHSETS));
+    nc.setNotify(EnumSet.of(NotifyType.NEW_PATCHSETS));
 
     try (ProjectConfigUpdate u = updateProject(project)) {
-      u.getConfig().putNotifyConfig("team", nc);
+      u.getConfig().putNotifyConfig("team", nc.build());
       u.save();
     }