diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/AbstractListenerWebSocketSession.java b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/AbstractListenerWebSocketSession.java
index 3cd34f9e969..8b99dae89b0 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/AbstractListenerWebSocketSession.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/AbstractListenerWebSocketSession.java
@@ -128,6 +128,8 @@ public abstract class AbstractListenerWebSocketSession<T> extends AbstractWebSoc
 	/**
 	 * Whether the underlying WebSocket API has flow control and can suspend and
 	 * resume the receiving of messages.
+	 * <p><strong>Note:</strong> Sub-classes are encouraged to start out in
+	 * suspended mode, if possible, and wait until demand is received.
 	 */
 	protected abstract boolean canSuspendReceiving();
 
@@ -238,7 +240,10 @@ public abstract class AbstractListenerWebSocketSession<T> extends AbstractWebSoc
 		}
 
 		void handleMessage(WebSocketMessage webSocketMessage) {
-			this.pendingMessages.offer(webSocketMessage);
+			if (!this.pendingMessages.offer(webSocketMessage)) {
+				throw new IllegalStateException("Too many messages received. " +
+						"Please ensure WebSocketSession.receive() is subscribed to.");
+			}
 			onDataAvailable();
 		}
 	}
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/JettyWebSocketSession.java b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/JettyWebSocketSession.java
index 449394b781b..0e16d70e6ac 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/JettyWebSocketSession.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/JettyWebSocketSession.java
@@ -57,6 +57,8 @@ public class JettyWebSocketSession extends AbstractListenerWebSocketSession<Sess
 			@Nullable MonoProcessor<Void> completionMono) {
 
 		super(session, ObjectUtils.getIdentityHexString(session), info, factory, completionMono);
+		// TODO: suspend causes failures if invoked at this stage
+		// suspendReceiving();
 	}
 
 
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/TomcatWebSocketSession.java b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/TomcatWebSocketSession.java
index 926977243f8..c966300d8d1 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/TomcatWebSocketSession.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/TomcatWebSocketSession.java
@@ -49,6 +49,7 @@ public class TomcatWebSocketSession extends StandardWebSocketSession {
 			MonoProcessor<Void> completionMono) {
 
 		super(session, info, factory, completionMono);
+		suspendReceiving();
 	}
 
 
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/UndertowWebSocketSession.java b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/UndertowWebSocketSession.java
index a78555c7e9e..122c7c50a6f 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/UndertowWebSocketSession.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/adapter/UndertowWebSocketSession.java
@@ -53,6 +53,7 @@ public class UndertowWebSocketSession extends AbstractListenerWebSocketSession<W
 			DataBufferFactory factory, @Nullable MonoProcessor<Void> completionMono) {
 
 		super(channel, ObjectUtils.getIdentityHexString(channel), info, factory, completionMono);
+		suspendReceiving();
 	}