diff --git a/indexing-service/src/main/java/io/druid/indexing/overlord/setup/WorkerSelectStrategy.java b/indexing-service/src/main/java/io/druid/indexing/overlord/setup/WorkerSelectStrategy.java
index 80103b6b721..46e400e994e 100644
--- a/indexing-service/src/main/java/io/druid/indexing/overlord/setup/WorkerSelectStrategy.java
+++ b/indexing-service/src/main/java/io/druid/indexing/overlord/setup/WorkerSelectStrategy.java
@@ -32,7 +32,7 @@ import java.util.Map;
 /**
  * The {@link io.druid.indexing.overlord.RemoteTaskRunner} uses this class to select a worker to assign tasks to.
  */
-@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type")
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type", defaultImpl = FillCapacityWorkerSelectStrategy.class)
 @JsonSubTypes(value = {
     @JsonSubTypes.Type(name = "fillCapacity", value = FillCapacityWorkerSelectStrategy.class)
 })