diff --git a/gradle.properties b/gradle.properties
index c9427c55..c2714fc3 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -6,4 +6,4 @@ org.gradle.parallel=true
 
 javaFormatVersion=0.0.34
 jmustacheVersion=1.15
-springFrameworkVersion=6.0.0-M5
\ No newline at end of file
+springFrameworkVersion=6.0.0-RC1
\ No newline at end of file
diff --git a/spring-restdocs-webtestclient/src/main/java/org/springframework/restdocs/webtestclient/WebTestClientRequestConverter.java b/spring-restdocs-webtestclient/src/main/java/org/springframework/restdocs/webtestclient/WebTestClientRequestConverter.java
index 30ebbaec..bf8b978d 100644
--- a/spring-restdocs-webtestclient/src/main/java/org/springframework/restdocs/webtestclient/WebTestClientRequestConverter.java
+++ b/spring-restdocs-webtestclient/src/main/java/org/springframework/restdocs/webtestclient/WebTestClientRequestConverter.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2021 the original author or authors.
+ * Copyright 2014-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -119,8 +119,9 @@ class WebTestClientRequestConverter implements RequestConverter<ExchangeResult>
 
 		@Override
 		public Flux<DataBuffer> getBody() {
-			DefaultDataBuffer buffer = new DefaultDataBufferFactory().allocateBuffer();
-			buffer.write(this.result.getRequestBodyContent());
+			byte[] requestBodyContent = this.result.getRequestBodyContent();
+			DefaultDataBuffer buffer = new DefaultDataBufferFactory().allocateBuffer(requestBodyContent.length);
+			buffer.write(requestBodyContent);
 			return Flux.fromArray(new DataBuffer[] { buffer });
 		}