diff --git a/java-client/src/test/java11/org/opensearch/client/opensearch/integTest/AbstractCrudIT.java b/java-client/src/test/java11/org/opensearch/client/opensearch/integTest/AbstractCrudIT.java
index f83247fa1b..0020a118eb 100644
--- a/java-client/src/test/java11/org/opensearch/client/opensearch/integTest/AbstractCrudIT.java
+++ b/java-client/src/test/java11/org/opensearch/client/opensearch/integTest/AbstractCrudIT.java
@@ -16,6 +16,7 @@
 import org.joda.time.DateTimeZone;
 import org.joda.time.format.DateTimeFormat;
 import org.opensearch.client.json.JsonData;
+import org.opensearch.client.opensearch._types.BuiltinScriptLanguage;
 import org.opensearch.client.opensearch._types.InlineScript;
 import org.opensearch.client.opensearch._types.OpenSearchException;
 import org.opensearch.client.opensearch._types.Refresh;
@@ -340,7 +341,7 @@ public void testBulkUpdateScript() throws IOException {
                 .script(
                     Script.of(
                         s -> s.inline(
-                            new InlineScript.Builder().lang("painless")
+                            new InlineScript.Builder().lang(l -> l.builtin(BuiltinScriptLanguage.Painless))
                                 .source("ctx._source.intValue += params.inc")
                                 .params("inc", JsonData.of(1))
                                 .build()
@@ -374,7 +375,7 @@ public void testBulkUpdateScriptUpsert() throws IOException {
                 .script(
                     Script.of(
                         s -> s.inline(
-                            new InlineScript.Builder().lang("painless")
+                            new InlineScript.Builder().lang(l -> l.builtin(BuiltinScriptLanguage.Painless))
                                 .source("ctx._source.intValue += params.inc")
                                 .params("inc", JsonData.of(1))
                                 .build()
@@ -411,7 +412,7 @@ public void testBulkUpdateScriptedUpsertUpdate() throws IOException {
                 .script(
                     Script.of(
                         s -> s.inline(
-                            new InlineScript.Builder().lang("painless")
+                            new InlineScript.Builder().lang(l -> l.builtin(BuiltinScriptLanguage.Painless))
                                 .source("ctx._source.intValue = ctx?._source?.intValue == null ? 7777 : 9999")
                                 .build()
                         )
@@ -441,7 +442,7 @@ public void testBulkUpdateScriptedUpsertInsert() throws IOException {
                 .script(
                     Script.of(
                         s -> s.inline(
-                            new InlineScript.Builder().lang("painless")
+                            new InlineScript.Builder().lang(l -> l.builtin(BuiltinScriptLanguage.Painless))
                                 .source("ctx._source.intValue = ctx?._source?.intValue == null ? 7777 : 9999")
                                 .build()
                         )
diff --git a/java-client/src/test/java11/org/opensearch/client/opensearch/integTest/AbstractMultiSearchRequestIT.java b/java-client/src/test/java11/org/opensearch/client/opensearch/integTest/AbstractMultiSearchRequestIT.java
index 0d35a11f7e..66623566a6 100644
--- a/java-client/src/test/java11/org/opensearch/client/opensearch/integTest/AbstractMultiSearchRequestIT.java
+++ b/java-client/src/test/java11/org/opensearch/client/opensearch/integTest/AbstractMultiSearchRequestIT.java
@@ -20,6 +20,7 @@
 import java.util.function.Function;
 import org.junit.Test;
 import org.opensearch.client.json.JsonData;
+import org.opensearch.client.opensearch._types.BuiltinScriptLanguage;
 import org.opensearch.client.opensearch._types.FieldSort;
 import org.opensearch.client.opensearch._types.FieldValue;
 import org.opensearch.client.opensearch._types.InlineScript;
@@ -208,7 +209,7 @@ public void shouldReturnMultiSearchesScriptFields() throws Exception {
             new ScriptField.Builder().script(
                 Script.of(
                     s -> s.inline(
-                        new InlineScript.Builder().lang("painless")
+                        new InlineScript.Builder().lang(l -> l.builtin(BuiltinScriptLanguage.Painless))
                             .source("doc['quantity'].value + params.inc")
                             .params("inc", JsonData.of(1))
                             .build()
diff --git a/samples/src/main/java/org/opensearch/client/samples/knn/KnnScriptScore.java b/samples/src/main/java/org/opensearch/client/samples/knn/KnnScriptScore.java
index eb0ccec60f..2277db6d13 100644
--- a/samples/src/main/java/org/opensearch/client/samples/knn/KnnScriptScore.java
+++ b/samples/src/main/java/org/opensearch/client/samples/knn/KnnScriptScore.java
@@ -67,7 +67,7 @@ public static void main(String[] args) {
                                 .script(
                                     sss -> sss.inline(
                                         i -> i.source("knn_score")
-                                            .lang("knn")
+                                            .lang(l -> l.custom("knn"))
                                             .params("field", JsonData.of("values"))
                                             .params("query_value", JsonData.of(searchVector))
                                             .params("space_type", JsonData.of("cosinesimil"))