diff --git a/spring-webmvc/src/main/java/org/springframework/web/servlet/function/DefaultServerRequest.java b/spring-webmvc/src/main/java/org/springframework/web/servlet/function/DefaultServerRequest.java
index 4775d37f2bc..3a4f4667d5a 100644
--- a/spring-webmvc/src/main/java/org/springframework/web/servlet/function/DefaultServerRequest.java
+++ b/spring-webmvc/src/main/java/org/springframework/web/servlet/function/DefaultServerRequest.java
@@ -438,7 +438,8 @@ class DefaultServerRequest implements ServerRequest {
 
 		@Override
 		public void clear() {
-			this.servletRequest.getAttributeNames().asIterator().forEachRemaining(this.servletRequest::removeAttribute);
+			List<String> attributeNames = Collections.list(this.servletRequest.getAttributeNames());
+			attributeNames.forEach(this.servletRequest::removeAttribute);
 		}
 
 		@Override