--- a/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/internal/common/SubscriberWrapper.java	Sun Dec 03 20:56:29 2017 +0000
+++ b/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/internal/common/SubscriberWrapper.java	Mon Dec 04 13:00:05 2017 +0000
@@ -76,6 +76,7 @@
     private final CompletableFuture<Void> cf;
     private final SequentialScheduler pushScheduler;
     private final AtomicReference<Throwable> errorRef = new AtomicReference<>();
+    final AtomicLong upstreamWindow = new AtomicLong(0);
 
     /**
      * Wraps the given downstream subscriber. For each call to {@link
@@ -309,8 +310,6 @@
         }
     }
 
-    AtomicLong upstreamWindow = new AtomicLong(0);
-
     void upstreamWindowUpdate() {
         long downstreamQueueSize = outputQ.size();
         long n = upstreamWindowUpdate(upstreamWindow.get(), downstreamQueueSize);
@@ -348,6 +347,12 @@
         upstreamSubscription.request(n);
     }
 
+    protected void requestMore() {
+        if (upstreamWindow.get() == 0) {
+            upstreamRequest(1);
+        }
+    }
+
     public long upstreamWindow() {
         return upstreamWindow.get();
     }