diff --git a/reactor-netty5-core/src/main/java/reactor/netty5/NettyOutbound.java b/reactor-netty5-core/src/main/java/reactor/netty5/NettyOutbound.java
index 6ae0840740..de87a0d368 100644
--- a/reactor-netty5-core/src/main/java/reactor/netty5/NettyOutbound.java
+++ b/reactor-netty5-core/src/main/java/reactor/netty5/NettyOutbound.java
@@ -42,6 +42,7 @@
 import reactor.core.publisher.Mono;
 
 import static reactor.netty5.ReactorNetty.PREDICATE_GROUP_BOUNDARY;
+import static reactor.netty5.ReactorNetty.PREDICATE_GROUP_FLUSH;
 
 /**
  * An outbound-traffic API delegating to an underlying {@link Channel}.
@@ -236,7 +237,13 @@ default NettyOutbound sendGroups(Publisher<? extends Publisher<? extends Buffer>
 				    .concatMap(p -> Flux.<Buffer>from(p)
 				                        .concatWith(Mono.just(BOUNDARY.copy(0, BOUNDARY.readableBytes(), true))), 32)
 				    .doFinally(sig -> BOUNDARY.close()),
-				ReactorNetty.PREDICATE_GROUP_FLUSH);
+				buf -> {
+					boolean flush = PREDICATE_GROUP_FLUSH.test(buf);
+					if (flush) {
+						buf.close();
+					}
+					return flush;
+				});
 	}
 
 	/**