diff --git a/pinot-query-planner/src/main/java/org/apache/pinot/query/routing/WorkerInstance.java b/pinot-query-planner/src/main/java/org/apache/pinot/query/routing/WorkerInstance.java
index 7ad6ee0b9c60..c7e6bcfbd573 100644
--- a/pinot-query-planner/src/main/java/org/apache/pinot/query/routing/WorkerInstance.java
+++ b/pinot-query-planner/src/main/java/org/apache/pinot/query/routing/WorkerInstance.java
@@ -41,7 +41,7 @@ public WorkerInstance(String hostname, int serverPort, int mailboxPort) {
   }
 
   private static InstanceConfig toInstanceConfig(String hostname, int serverPort, int mailboxPort) {
-    String server = String.format("%s_%d", hostname, serverPort);
+    String server = String.format("%s%s_%d", CommonConstants.Helix.PREFIX_OF_SERVER_INSTANCE, hostname, serverPort);
     InstanceConfig instanceConfig = InstanceConfig.toInstanceConfig(server);
     ZNRecord znRecord = instanceConfig.getRecord();
     Map<String, String> simpleFields = znRecord.getSimpleFields();
diff --git a/pinot-query-planner/src/test/java/org/apache/pinot/query/QueryEnvironmentTest.java b/pinot-query-planner/src/test/java/org/apache/pinot/query/QueryEnvironmentTest.java
index d63c5c55c7dc..9f4778743bc2 100644
--- a/pinot-query-planner/src/test/java/org/apache/pinot/query/QueryEnvironmentTest.java
+++ b/pinot-query-planner/src/test/java/org/apache/pinot/query/QueryEnvironmentTest.java
@@ -68,18 +68,18 @@ public void testQueryAndAssertStageContentForJoin()
         // table scan stages; for tableA it should have 2 hosts, for tableB it should have only 1
         Assert.assertEquals(
             e.getValue().getServerInstances().stream().map(ServerInstance::toString).collect(Collectors.toList()),
-            tables.get(0).equals("a") ? ImmutableList.of("localhost_1", "localhost_2")
-                : ImmutableList.of("localhost_1"));
+            tables.get(0).equals("a") ? ImmutableList.of("Server_localhost_1", "Server_localhost_2")
+                : ImmutableList.of("Server_localhost_1"));
       } else if (!PlannerUtils.isRootStage(e.getKey())) {
         // join stage should have both servers used.
         Assert.assertEquals(
             e.getValue().getServerInstances().stream().map(ServerInstance::toString).collect(Collectors.toList()),
-            ImmutableList.of("localhost_1", "localhost_2"));
+            ImmutableList.of("Server_localhost_1", "Server_localhost_2"));
       } else {
         // reduce stage should have the reducer instance.
         Assert.assertEquals(
             e.getValue().getServerInstances().stream().map(ServerInstance::toString).collect(Collectors.toList()),
-            ImmutableList.of("localhost_3"));
+            ImmutableList.of("Server_localhost_3"));
       }
     }
   }