diff --git a/src/main/java/org/opensearch/performanceanalyzer/collectors/ShardStateCollector.java b/src/main/java/org/opensearch/performanceanalyzer/collectors/ShardStateCollector.java
index 95f8cdd6..a1246054 100644
--- a/src/main/java/org/opensearch/performanceanalyzer/collectors/ShardStateCollector.java
+++ b/src/main/java/org/opensearch/performanceanalyzer/collectors/ShardStateCollector.java
@@ -68,7 +68,7 @@ public void collectMetrics(long startTime) {
         value.append(PerformanceAnalyzerMetrics.getJsonCurrentMilliSeconds())
                 .append(PerformanceAnalyzerMetrics.sMetricNewLineDelimitor);
         RoutingTable routingTable = clusterState.routingTable();
-        String[] indices = routingTable.indicesRouting().keys().toArray(String.class);
+        String[] indices = routingTable.indicesRouting().keySet().toArray(new String[0]);
         for (String index : indices) {
             List<ShardRouting> allShardsIndex = routingTable.allShards(index);
             value.append(