diff --git a/java/com/google/gerrit/index/query/AndPredicate.java b/java/com/google/gerrit/index/query/AndPredicate.java
index 23ae312..fda961d 100644
--- a/java/com/google/gerrit/index/query/AndPredicate.java
+++ b/java/com/google/gerrit/index/query/AndPredicate.java
@@ -134,7 +134,7 @@
       cmp = a.estimateCost() - b.estimateCost();
     }
 
-    if (cmp == 0 && a instanceof DataSource && b instanceof DataSource) {
+    if (cmp == 0 && a instanceof DataSource) {
       DataSource<?> as = (DataSource<?>) a;
       DataSource<?> bs = (DataSource<?>) b;
       cmp = as.getCardinality() - bs.getCardinality();