diff --git a/src/main/java/org/springframework/data/elasticsearch/client/elc/NativeQueryBuilder.java b/src/main/java/org/springframework/data/elasticsearch/client/elc/NativeQueryBuilder.java
index c2c6ae7e2..3a831e4bd 100644
--- a/src/main/java/org/springframework/data/elasticsearch/client/elc/NativeQueryBuilder.java
+++ b/src/main/java/org/springframework/data/elasticsearch/client/elc/NativeQueryBuilder.java
@@ -185,7 +185,7 @@ public NativeQueryBuilder withSearchExtensions(Map<String, JsonData> searchExten
 
 		Assert.notNull(searchExtensions, "searchExtensions must not be null");
 
-		searchExtensions.putAll(searchExtensions);
+		this.searchExtensions.putAll(searchExtensions);
 		return this;
 	}