diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java
index a7005d7..320453e 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/IsWatchedByPredicate.java
@@ -73,7 +73,9 @@
       }
 
       if (p != null && f != null) {
-        r.add(and(p, f));
+        @SuppressWarnings("unchecked")
+        Predicate<ChangeData> andPredicate = and(p, f);
+        r.add(andPredicate);
       } else if (p != null) {
         r.add(p);
       } else if (f != null) {