diff --git a/integ-test/src/test/java/org/opensearch/sql/legacy/RestIntegTestCase.java b/integ-test/src/test/java/org/opensearch/sql/legacy/RestIntegTestCase.java
index e6f567e2dba..dd48d821145 100644
--- a/integ-test/src/test/java/org/opensearch/sql/legacy/RestIntegTestCase.java
+++ b/integ-test/src/test/java/org/opensearch/sql/legacy/RestIntegTestCase.java
@@ -44,10 +44,9 @@
 import org.junit.Before;
 import org.opensearch.client.Request;
 import org.opensearch.client.Response;
-import org.opensearch.common.Strings;
-import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.rest.RestStatus;
+import org.opensearch.core.xcontent.XContentBuilder;
 
 /**
  * SQL plugin integration test base class (migrated from SQLIntegTestCase)
@@ -164,7 +163,7 @@ protected static void updateClusterSetting(String settingKey, Object value, bool
         .endObject()
         .endObject();
     Request request = new Request("PUT", "_cluster/settings");
-    request.setJsonEntity(Strings.toString(builder));
+    request.setJsonEntity(builder.toString());
     Response response = client().performRequest(request);
     Assert
         .assertEquals(RestStatus.OK, RestStatus.fromCode(response.getStatusLine().getStatusCode()));
diff --git a/legacy/src/main/java/org/opensearch/sql/legacy/query/planner/physical/node/join/BlockHashJoin.java b/legacy/src/main/java/org/opensearch/sql/legacy/query/planner/physical/node/join/BlockHashJoin.java
index cfb6265e523..19c0ae41d22 100644
--- a/legacy/src/main/java/org/opensearch/sql/legacy/query/planner/physical/node/join/BlockHashJoin.java
+++ b/legacy/src/main/java/org/opensearch/sql/legacy/query/planner/physical/node/join/BlockHashJoin.java
@@ -16,8 +16,8 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import org.opensearch.common.Strings;
 import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.core.common.Strings;
 import org.opensearch.index.query.BoolQueryBuilder;
 import org.opensearch.sql.legacy.query.planner.core.ExecuteParams;
 import org.opensearch.sql.legacy.query.planner.physical.PhysicalOperator;
diff --git a/legacy/src/main/java/org/opensearch/sql/legacy/query/planner/physical/node/scroll/Scroll.java b/legacy/src/main/java/org/opensearch/sql/legacy/query/planner/physical/node/scroll/Scroll.java
index 6dd8ff6e890..05d538d3206 100644
--- a/legacy/src/main/java/org/opensearch/sql/legacy/query/planner/physical/node/scroll/Scroll.java
+++ b/legacy/src/main/java/org/opensearch/sql/legacy/query/planner/physical/node/scroll/Scroll.java
@@ -13,9 +13,9 @@
 import org.opensearch.action.search.ClearScrollResponse;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.client.Client;
-import org.opensearch.common.Strings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.core.common.Strings;
 import org.opensearch.index.query.BoolQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;
 import org.opensearch.search.SearchHit;
diff --git a/legacy/src/main/java/org/opensearch/sql/legacy/utils/JsonPrettyFormatter.java b/legacy/src/main/java/org/opensearch/sql/legacy/utils/JsonPrettyFormatter.java
index 827f968bde3..ecc86877ee9 100644
--- a/legacy/src/main/java/org/opensearch/sql/legacy/utils/JsonPrettyFormatter.java
+++ b/legacy/src/main/java/org/opensearch/sql/legacy/utils/JsonPrettyFormatter.java
@@ -8,7 +8,6 @@
 
 import com.fasterxml.jackson.core.JsonFactory;
 import java.io.IOException;
-import org.opensearch.common.Strings;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.json.JsonXContentParser;
@@ -37,7 +36,7 @@ public static String format(String jsonString) throws IOException {
         ){
             contentBuilder.copyCurrentStructure(contentParser);
         }
-        return Strings.toString(contentBuilder);
+        return contentBuilder.toString();
     }
 
     private JsonPrettyFormatter() {
diff --git a/legacy/src/test/java/org/opensearch/sql/legacy/plugin/RestSQLQueryActionCursorFallbackTest.java b/legacy/src/test/java/org/opensearch/sql/legacy/plugin/RestSQLQueryActionCursorFallbackTest.java
index a11f4c47d7a..c885ffae6a8 100644
--- a/legacy/src/test/java/org/opensearch/sql/legacy/plugin/RestSQLQueryActionCursorFallbackTest.java
+++ b/legacy/src/test/java/org/opensearch/sql/legacy/plugin/RestSQLQueryActionCursorFallbackTest.java
@@ -22,7 +22,6 @@
 import org.mockito.Mockito;
 import org.mockito.junit.MockitoJUnitRunner;
 import org.opensearch.client.node.NodeClient;
-import org.opensearch.common.Strings;
 import org.opensearch.common.inject.Injector;
 import org.opensearch.common.inject.ModulesBuilder;
 import org.opensearch.common.util.concurrent.ThreadContext;
@@ -96,7 +95,7 @@ private static SQLQueryRequest createSqlQueryRequest(String query, Optional<Stri
       builder.field("fetch_size").value(fetchSize.get());
     }
     builder.endObject();
-    JSONObject jsonContent = new JSONObject(Strings.toString(builder));
+    JSONObject jsonContent = new JSONObject(builder.toString());
 
     return  new SQLQueryRequest(jsonContent, query, QUERY_API_ENDPOINT,
         Map.of("format", "jdbc"), cursorId.orElse(""));
diff --git a/legacy/src/test/java/org/opensearch/sql/legacy/unittest/QueryFunctionsTest.java b/legacy/src/test/java/org/opensearch/sql/legacy/unittest/QueryFunctionsTest.java
index 9c1328eaa83..0ebf89e2966 100644
--- a/legacy/src/test/java/org/opensearch/sql/legacy/unittest/QueryFunctionsTest.java
+++ b/legacy/src/test/java/org/opensearch/sql/legacy/unittest/QueryFunctionsTest.java
@@ -24,8 +24,8 @@
 import org.junit.Test;
 import org.mockito.Mockito;
 import org.opensearch.client.Client;
-import org.opensearch.common.Strings;
 import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.core.common.Strings;
 import org.opensearch.index.query.AbstractQueryBuilder;
 import org.opensearch.index.query.MultiMatchQueryBuilder;
 import org.opensearch.search.builder.SearchSourceBuilder.ScriptField;
diff --git a/plugin/src/main/java/org/opensearch/sql/plugin/rest/RestQuerySettingsAction.java b/plugin/src/main/java/org/opensearch/sql/plugin/rest/RestQuerySettingsAction.java
index 7b51b475039..b15b4dddd60 100644
--- a/plugin/src/main/java/org/opensearch/sql/plugin/rest/RestQuerySettingsAction.java
+++ b/plugin/src/main/java/org/opensearch/sql/plugin/rest/RestQuerySettingsAction.java
@@ -17,7 +17,6 @@
 import org.opensearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
 import org.opensearch.client.Requests;
 import org.opensearch.client.node.NodeClient;
-import org.opensearch.common.Strings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -109,7 +108,7 @@ private Settings getAndFilterSettings(Map<String, ?> source) {
       XContentBuilder builder = XContentFactory.jsonBuilder();
       builder.map(source);
       Settings.Builder settingsBuilder = Settings.builder()
-          .loadFromSource(Strings.toString(builder), builder.contentType());
+          .loadFromSource(builder.toString(), builder.contentType());
       settingsBuilder.keys().removeIf(key -> {
         for (String prefix : SETTINGS_PREFIX) {
           if (key.startsWith(prefix)) {
