diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java
index 9eed2bf0030..e29cb2279e4 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java
@@ -195,12 +195,12 @@ public class HandshakeWebSocketService implements WebSocketService, Lifecycle {
 
 		if (HttpMethod.GET == method) {
 			if (!"WebSocket".equalsIgnoreCase(headers.getUpgrade())) {
-				return handleBadRequest(exchange, "Invalid 'Upgrade' header: " + headers);
+				return handleBadRequest(exchange, "Can \"Upgrade\" only to \"WebSocket\".");
 			}
 
 			List<String> connectionValue = headers.getConnection();
 			if (!connectionValue.contains("Upgrade") && !connectionValue.contains("upgrade")) {
-				return handleBadRequest(exchange, "Invalid 'Connection' header: " + headers);
+				return handleBadRequest(exchange, "\"Connection\" must be \"upgrade\".");
 			}
 
 			String key = headers.getFirst(SEC_WEBSOCKET_KEY);