diff --git a/test/jdk/java/net/httpclient/http2/StreamFlowControlTest.java b/test/jdk/java/net/httpclient/http2/StreamFlowControlTest.java
index 3e4ee4864f5..32f96c7ed4b 100644
--- a/test/jdk/java/net/httpclient/http2/StreamFlowControlTest.java
+++ b/test/jdk/java/net/httpclient/http2/StreamFlowControlTest.java
@@ -82,6 +82,9 @@ public class StreamFlowControlTest {
     String http2URI;
     String https2URI;
     final AtomicInteger reqid = new AtomicInteger();
+    final static int WINDOW =
+            Integer.getInteger("jdk.httpclient.windowsize", 2 * 16 * 1024);
+
 
 
     @DataProvider(name = "variants")
@@ -147,7 +150,11 @@ public class StreamFlowControlTest {
                     // the window is exceeded...
                     long wait = uri.startsWith("https://") ? 800 : 500;
                     try (InputStream is = response.body()) {
-                        sleep(wait);
+                        byte[] discard = new byte[WINDOW/4];
+                        for (int j=0; j<2; j++) {
+                            sleep(wait);
+                            if (is.read(discard) < 0) break;
+                        }
                         is.readAllBytes();
                     }
                     // we could fail here if we haven't waited long enough
@@ -205,7 +212,11 @@ public class StreamFlowControlTest {
                     sent.join();
                     long wait = uri.startsWith("https://") ? 800 : 350;
                     try (InputStream is = response.body()) {
-                        sleep(wait);
+                        byte[] discard = new byte[WINDOW/4];
+                        for (int j=0; j<2; j++) {
+                            sleep(wait);
+                            if (is.read(discard) < 0) break;
+                        }
                         is.readAllBytes();
                     }
                     // we could fail here if we haven't waited long enough
@@ -316,17 +327,16 @@ public class StreamFlowControlTest {
                     bytes = "no request body!"
                             .repeat(100).getBytes(StandardCharsets.UTF_8);
                 }
-                int window = Integer.getInteger("jdk.httpclient.windowsize", 2 * 16 * 1024);
                 final int maxChunkSize;
                 if (t instanceof FCHttp2TestExchange fct) {
-                    maxChunkSize = Math.min(window, fct.conn.getMaxFrameSize());
+                    maxChunkSize = Math.min(WINDOW, fct.conn.getMaxFrameSize());
                 } else {
-                    maxChunkSize = Math.min(window, SettingsFrame.MAX_FRAME_SIZE);
+                    maxChunkSize = Math.min(WINDOW, SettingsFrame.MAX_FRAME_SIZE);
                 }
                 byte[] resp = bytes.length <= maxChunkSize
                         ? bytes
                         : Arrays.copyOfRange(bytes, 0, maxChunkSize);
-                int max = (window / resp.length) + 2;
+                int max = (WINDOW / resp.length) + 2;
                 // send in chunks
                 t.sendResponseHeaders(200, 0);
                 for (int i = 0; i <= max; i++) {