diff --git a/java/com/google/gerrit/server/mail/send/ProjectWatch.java b/java/com/google/gerrit/server/mail/send/ProjectWatch.java
index d71033a..94a0e37 100644
--- a/java/com/google/gerrit/server/mail/send/ProjectWatch.java
+++ b/java/com/google/gerrit/server/mail/send/ProjectWatch.java
@@ -267,8 +267,8 @@
     return p == null || p.asMatchable().match(changeData);
   }
 
-  private static class WatcherChangeQueryBuilder extends ChangeQueryBuilder {
-    private WatcherChangeQueryBuilder(Arguments args) {
+  public static class WatcherChangeQueryBuilder extends ChangeQueryBuilder {
+    public WatcherChangeQueryBuilder(Arguments args) {
       super(args);
     }
 
@@ -301,5 +301,16 @@
       // predicates.
       return Predicate.or(predicates);
     }
+
+    @Override
+    public Predicate<ChangeData> is(String value) throws QueryParseException {
+      if ("watched".equalsIgnoreCase(value)) {
+        // project watches cannot use "is:watched" as this would trigger an endless loop in
+        // IsWatchedByPredicate
+        throw new QueryParseException(
+            String.format("Operator 'is:watched' cannot be used in project watches."));
+      }
+      return super.is(value);
+    }
   }
 }
diff --git a/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java b/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java
index 046d24c..7144d3e 100644
--- a/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java
+++ b/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java
@@ -15,18 +15,21 @@
 package com.google.gerrit.server.query.change;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.index.query.AndPredicate;
 import com.google.gerrit.index.query.Predicate;
-import com.google.gerrit.index.query.QueryBuilder;
 import com.google.gerrit.index.query.QueryParseException;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.account.ProjectWatches.ProjectWatchKey;
+import com.google.gerrit.server.mail.send.ProjectWatch;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
 public class IsWatchedByPredicate extends AndPredicate<ChangeData> {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   protected static String describe(CurrentUser user) {
     if (user.isIdentifiedUser()) {
       return user.getAccountId().toString();
@@ -44,20 +47,16 @@
   protected static ImmutableList<Predicate<ChangeData>> filters(ChangeQueryBuilder.Arguments args)
       throws QueryParseException {
     List<Predicate<ChangeData>> r = new ArrayList<>();
-    ChangeQueryBuilder builder = new ChangeQueryBuilder(args);
+    ProjectWatch.WatcherChangeQueryBuilder builder =
+        new ProjectWatch.WatcherChangeQueryBuilder(args);
     for (ProjectWatchKey w : getWatches(args)) {
       Predicate<ChangeData> f = null;
       if (w.filter() != null) {
         try {
           f = builder.parse(w.filter());
-          if (QueryBuilder.find(f, IsWatchedByPredicate.class) != null) {
-            // If the query is going to infinite loop, assume it
-            // will never match and return null. Yes this test
-            // prevents you from having a filter that matches what
-            // another user is filtering on. :-)
-            continue;
-          }
         } catch (QueryParseException e) {
+          logger.atFine().log(
+              "Ignoring non-parseable filter of project watch %s: %s", w, e.getMessage());
           continue;
         }
       }
diff --git a/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java b/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
index 014933f..5accd00 100644
--- a/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
+++ b/javatests/com/google/gerrit/acceptance/server/project/ProjectWatchIT.java
@@ -694,4 +694,26 @@
     assertThat(m.body()).contains("Change subject: TRIGGER\n");
     assertThat(m.body()).contains("Gerrit-PatchSet: 1\n");
   }
+
+  @Test
+  public void watchThatUsesIsWatchedDoesntMatchAnything() throws Exception {
+    String watchedProject = projectOperations.newProject().create().get();
+
+    // configure a project watch for user that uses "is:watched"
+    requestScopeOperations.setApiUser(user.id());
+    watch(watchedProject, "is:watched");
+
+    // create a change as admin user that may trigger the project watch
+    requestScopeOperations.setApiUser(admin.id());
+    TestRepository<InMemoryRepository> watchedRepo =
+        cloneProject(Project.nameKey(watchedProject), admin);
+    PushOneCommit.Result r =
+        pushFactory
+            .create(admin.newIdent(), watchedRepo, "subject", "a.txt", "a1")
+            .to("refs/for/master");
+    r.assertOkStatus();
+
+    // assert that there was no email notification for user
+    assertThat(sender.getMessages()).isEmpty();
+  }
 }
diff --git a/javatests/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java b/javatests/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
index 7a7cff5..a0aad96 100644
--- a/javatests/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
+++ b/javatests/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
@@ -3627,6 +3627,24 @@
   }
 
   @Test
+  public void watched_projectWatchThatUsesIsWatchedIsIgnored() throws Exception {
+    Project.NameKey project = Project.nameKey("repo");
+    createProject(project);
+    insert(project, newChangeWithStatus(project, Change.Status.NEW));
+
+    List<ProjectWatchInfo> projectsToWatch = new ArrayList<>();
+    ProjectWatchInfo pwi = new ProjectWatchInfo();
+    pwi.project = "repo";
+    pwi.filter = "is:watched";
+    pwi.notifyNewChanges = true;
+    projectsToWatch.add(pwi);
+    gApi.accounts().self().setWatchedProjects(projectsToWatch);
+    resetUser();
+
+    assertQuery("is:watched");
+  }
+
+  @Test
   public void trackingid() throws Exception {
     Project.NameKey project = Project.nameKey("repo");
     repo = createAndOpenProject(project);