4 files changed, 20 insertions, 0 deletions
diff --git a/src/network/access/qhttpnetworkrequest.cpp b/src/network/access/qhttpnetworkrequest.cpp
index f370445059..f419ee2673 100644
--- a/src/network/access/qhttpnetworkrequest.cpp
+++ b/src/network/access/qhttpnetworkrequest.cpp
@@ -365,6 +365,16 @@ void QHttpNetworkRequest::setHTTP2Direct(bool b)
     d->http2Direct = b;
 }
 
+bool QHttpNetworkRequest::isH2cAllowed() const
+{
+    return qEnvironmentVariableIsSet("QT_NETWORK_H2C_ALLOWED");
+}
+
+void QHttpNetworkRequest::setH2cAllowed(bool b)
+{
+    Q_UNUSED(b);
+}
+
 bool QHttpNetworkRequest::withCredentials() const
 {
     return d->withCredentials;
diff --git a/src/network/access/qhttpnetworkrequest_p.h b/src/network/access/qhttpnetworkrequest_p.h
index 50fdd64290..f4c1d7fb8c 100644
--- a/src/network/access/qhttpnetworkrequest_p.h
+++ b/src/network/access/qhttpnetworkrequest_p.h
@@ -125,6 +125,9 @@ public:
     bool isHTTP2Direct() const;
     void setHTTP2Direct(bool b);
 
+    bool isH2cAllowed() const;
+    void setH2cAllowed(bool b);
+
     bool withCredentials() const;
     void setWithCredentials(bool b);
 
diff --git a/src/network/access/qhttpthreaddelegate.cpp b/src/network/access/qhttpthreaddelegate.cpp
index 50a14b6258..243492d466 100644
--- a/src/network/access/qhttpthreaddelegate.cpp
+++ b/src/network/access/qhttpthreaddelegate.cpp
@@ -290,6 +290,12 @@ void QHttpThreadDelegate::startRequest()
         connectionType = QHttpNetworkConnection::ConnectionTypeHTTP2Direct;
     }
 
+    // Use HTTP/1.1 if h2c is not allowed and we would otherwise choose to use it
+    if (!ssl && connectionType == QHttpNetworkConnection::ConnectionTypeHTTP2
+        && !httpRequest.isH2cAllowed()) {
+        connectionType = QHttpNetworkConnection::ConnectionTypeHTTP;
+    }
+
 #if QT_CONFIG(ssl)
     // See qnetworkreplyhttpimpl, delegate's initialization code.
     Q_ASSERT(!ssl || incomingSslConfiguration.data());
diff --git a/tests/auto/network/access/http2/tst_http2.cpp b/tests/auto/network/access/http2/tst_http2.cpp
index 432b35e5c6..4a6e34eb7b 100644
--- a/tests/auto/network/access/http2/tst_http2.cpp
+++ b/tests/auto/network/access/http2/tst_http2.cpp
@@ -223,6 +223,7 @@ tst_Http2::~tst_Http2()
 void tst_Http2::init()
 {
     manager.reset(new QNetworkAccessManager);
+    qputenv("QT_NETWORK_H2C_ALLOWED", "1");
 }
 
 void tst_Http2::singleRequest_data()