diff --git a/util/src/test/java/io/grpc/util/MultiChildLoadBalancerTest.java b/util/src/test/java/io/grpc/util/MultiChildLoadBalancerTest.java
index 4f4501b3676..fd472615390 100644
--- a/util/src/test/java/io/grpc/util/MultiChildLoadBalancerTest.java
+++ b/util/src/test/java/io/grpc/util/MultiChildLoadBalancerTest.java
@@ -286,6 +286,7 @@ private String addressesOnlyString(EquivalentAddressGroup eag) {
     return "[" + withoutAttrs.replaceAll("[\\[\\]]", "") + "]";
   }
 
+  @SuppressWarnings("MixedMutabilityReturnType")
   private List<LoadBalancer.Subchannel> getList(LoadBalancer.SubchannelPicker picker) {
     if (picker instanceof LoadBalancer.FixedResultPicker) {
       LoadBalancer.Subchannel subchannel = picker.pickSubchannel(null).getSubchannel();