diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/elasticsearch/RestClientBuilderCustomizer.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/elasticsearch/RestClientBuilderCustomizer.java
index 0e8fd4001a..685929d908 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/elasticsearch/RestClientBuilderCustomizer.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/elasticsearch/RestClientBuilderCustomizer.java
@@ -34,6 +34,11 @@ public interface RestClientBuilderCustomizer {
 
 	/**
 	 * Customize the {@link RestClientBuilder}.
+	 * <p>
+	 * Possibly overrides customizations made with the {@code "spring.elasticsearch.rest"}
+	 * configuration properties namespace. For more targeted changes, see
+	 * {@link #customize(HttpAsyncClientBuilder)} and
+	 * {@link #customize(RequestConfig.Builder)}.
 	 * @param builder the builder to customize
 	 */
 	void customize(RestClientBuilder builder);
@@ -41,6 +46,7 @@ public interface RestClientBuilderCustomizer {
 	/**
 	 * Customize the {@link HttpAsyncClientBuilder}.
 	 * @param builder the builder
+	 * @since 2.3.0
 	 */
 	default void customize(HttpAsyncClientBuilder builder) {
 	}
@@ -48,6 +54,7 @@ public interface RestClientBuilderCustomizer {
 	/**
 	 * Customize the {@link RequestConfig.Builder}.
 	 * @param builder the builder
+	 * @since 2.3.0
 	 */
 	default void customize(RequestConfig.Builder builder) {
 	}