diff --git a/src/network/access/qhttp2connection.cpp b/src/network/access/qhttp2connection.cpp
index 03ae5935ace..7f1a776e1c0 100644
--- a/src/network/access/qhttp2connection.cpp
+++ b/src/network/access/qhttp2connection.cpp
@@ -476,6 +476,8 @@ void QHttp2Stream::maybeResumeUpload()
             isUploadBlocked());
     if (isUploadingDATA() && !isUploadBlocked())
         internalSendDATA();
+    else
+        getConnection()->m_blockedStreams.insert(streamID());
 }
 
 /*!
@@ -891,6 +893,10 @@ QHttp2Stream *QHttp2Connection::createStreamInternal_impl(quint32 streamID)
     stream = new QHttp2Stream(this, streamID);
     stream->m_recvWindow = streamInitialReceiveWindowSize;
     stream->m_sendWindow = streamInitialSendWindowSize;
+
+    connect(stream, &QHttp2Stream::uploadBlocked, this, [this, stream] {
+        m_blockedStreams.insert(stream->streamID());
+    });
     return stream;
 }
 
@@ -1740,10 +1746,13 @@ void QHttp2Connection::handleWINDOW_UPDATE()
         if (!valid || qAddOverflow(sessionSendWindowSize, qint32(delta), &sum))
             return connectionError(PROTOCOL_ERROR, "WINDOW_UPDATE invalid delta");
         sessionSendWindowSize = sum;
-        for (const auto &stream : std::as_const(m_streams)) {
+
+        // Stream may have been unblocked, so maybe try to write again:
+        const auto blockedStreams = std::exchange(m_blockedStreams, {});
+        for (quint32 blockedStreamID : blockedStreams) {
+            const QPointer<QHttp2Stream> stream = m_streams.value(blockedStreamID);
             if (!stream || !stream->isActive())
                 continue;
-            // Stream may have been unblocked, so maybe try to write again
             if (stream->isUploadingDATA() && !stream->isUploadBlocked())
                 QMetaObject::invokeMethod(stream, &QHttp2Stream::maybeResumeUpload,
                                           Qt::QueuedConnection);
diff --git a/src/network/access/qhttp2connection_p.h b/src/network/access/qhttp2connection_p.h
index 8bb49176a60..aa7f046cea6 100644
--- a/src/network/access/qhttp2connection_p.h
+++ b/src/network/access/qhttp2connection_p.h
@@ -19,6 +19,7 @@
 
 #include <QtCore/qobject.h>
 #include <QtCore/qhash.h>
+#include <QtCore/qset.h>
 #include <QtCore/qvarlengtharray.h>
 #include <QtCore/qxpfunctional.h>
 #include <QtNetwork/qhttp2configuration.h>
@@ -325,6 +326,7 @@ private:
 
     QHttp2Configuration m_config;
     QHash<quint32, QPointer<QHttp2Stream>> m_streams;
+    QSet<quint32> m_blockedStreams;
     QHash<QUrl, quint32> m_promisedStreams;
     QList<quint32> m_resetStreamIDs;