diff --git a/src/main/java/io/kestra/plugin/elasticsearch/AbstractLoad.java b/src/main/java/io/kestra/plugin/elasticsearch/AbstractLoad.java
index d7f4c68..1d8fd1b 100644
--- a/src/main/java/io/kestra/plugin/elasticsearch/AbstractLoad.java
+++ b/src/main/java/io/kestra/plugin/elasticsearch/AbstractLoad.java
@@ -6,6 +6,7 @@
 import io.kestra.core.models.executions.metrics.Timer;
 import io.kestra.core.models.tasks.RunnableTask;
 import io.kestra.core.runners.RunContext;
+import io.kestra.core.serializers.FileSerde;
 import io.swagger.v3.oas.annotations.media.Schema;
 import lombok.*;
 import lombok.experimental.SuperBuilder;
@@ -56,7 +57,7 @@ public AbstractLoad.Output run(RunContext runContext) throws Exception {
 
         try (
             RestClientTransport transport = this.connection.client(runContext);
-            BufferedReader inputStream = new BufferedReader(new InputStreamReader(runContext.storage().getFile(from)))
+            BufferedReader inputStream = new BufferedReader(new InputStreamReader(runContext.storage().getFile(from)), FileSerde.BUFFER_SIZE)
         ) {
             OpenSearchClient client = new OpenSearchClient(transport);
             AtomicLong count = new AtomicLong();
diff --git a/src/main/java/io/kestra/plugin/elasticsearch/Load.java b/src/main/java/io/kestra/plugin/elasticsearch/Load.java
index c0f2712..869ddb8 100644
--- a/src/main/java/io/kestra/plugin/elasticsearch/Load.java
+++ b/src/main/java/io/kestra/plugin/elasticsearch/Load.java
@@ -13,12 +13,12 @@
 import lombok.experimental.SuperBuilder;
 
 import java.io.BufferedReader;
+import java.io.IOException;
 import java.util.Map;
 import jakarta.validation.constraints.NotNull;
 import org.opensearch.client.opensearch.core.bulk.BulkOperation;
 import org.opensearch.client.opensearch.core.bulk.IndexOperation;
 import reactor.core.publisher.Flux;
-import reactor.core.publisher.FluxSink;
 
 import static io.kestra.core.utils.Rethrow.throwFunction;
 
@@ -73,9 +73,8 @@ public class Load extends AbstractLoad implements RunnableTask<Load.Output> {
 
     @SuppressWarnings("unchecked")
     @Override
-    protected Flux<BulkOperation> source(RunContext runContext, BufferedReader inputStream) throws IllegalVariableEvaluationException {
-        return Flux
-            .create(FileSerde.reader(inputStream), FluxSink.OverflowStrategy.BUFFER)
+    protected Flux<BulkOperation> source(RunContext runContext, BufferedReader inputStream) throws IllegalVariableEvaluationException, IOException {
+        return FileSerde.readAll(inputStream)
             .map(throwFunction(o -> {
                 Map<String, ?> values = (Map<String, ?>) o;