diff --git a/.cmake.conf b/.cmake.conf
index f4279a6..a719905 100644
--- a/.cmake.conf
+++ b/.cmake.conf
@@ -4,4 +4,5 @@ set(QT_EXTRA_INTERNAL_TARGET_DEFINES
     "QT_NO_CONTEXTLESS_CONNECT=1"
     "QT_NO_FOREACH=1"
     "QT_NO_QASCONST=1"
+    "QT_NO_URL_CAST_FROM_STRING=1"
 )
diff --git a/src/coap/qcoaprequest.cpp b/src/coap/qcoaprequest.cpp
index fe6e59d..37eb70a 100644
--- a/src/coap/qcoaprequest.cpp
+++ b/src/coap/qcoaprequest.cpp
@@ -10,6 +10,8 @@
 #include <QtCore/qloggingcategory.h>
 #include <QtCore/QDebug>
 
+using namespace Qt::StringLiterals;
+
 QT_BEGIN_NAMESPACE
 
 namespace {
@@ -259,7 +261,7 @@ QUrl QCoapRequestPrivate::adjustedUrl(const QUrl &url, bool secure)
     if (url.host().isEmpty() && url.isRelative()) {
         // In some cases host address is mistaken for part of the relative path,
         // prepending the scheme fixes this.
-        finalizedUrl = url.toString().prepend(scheme + QLatin1String("://"));
+        finalizedUrl = QUrl{scheme + "://"_L1 + url.toString()};
     } else if (url.scheme().isEmpty()) {
         finalizedUrl.setScheme(scheme);
     }
diff --git a/tests/auto/qcoapclient/tst_qcoapclient.cpp b/tests/auto/qcoapclient/tst_qcoapclient.cpp
index 16a5110..4ee789b 100644
--- a/tests/auto/qcoapclient/tst_qcoapclient.cpp
+++ b/tests/auto/qcoapclient/tst_qcoapclient.cpp
@@ -217,9 +217,9 @@ public slots:
 void tst_QCoapClient::initTestCase()
 {
 #if defined(COAP_TEST_SERVER_IP) || defined(QT_TEST_SERVER)
-    QVERIFY2(waitForHost(testServerHost()), "Failed to connect to Californium plugtest server.");
+    QVERIFY2(waitForHost(QUrl{testServerHost()}), "Failed to connect to Californium plugtest server.");
 #if QT_CONFIG(dtls)
-    QVERIFY2(waitForHost(timeServerUrl(), QtCoap::SecurityMode::Certificate),
+    QVERIFY2(waitForHost(QUrl{timeServerUrl()}, QtCoap::SecurityMode::Certificate),
              "Failed to connect to FreeCoAP sample time server.");
 #endif
 #endif
diff --git a/tests/auto/qcoapinternalrequest/tst_qcoapinternalrequest.cpp b/tests/auto/qcoapinternalrequest/tst_qcoapinternalrequest.cpp
index 2119913..941639b 100644
--- a/tests/auto/qcoapinternalrequest/tst_qcoapinternalrequest.cpp
+++ b/tests/auto/qcoapinternalrequest/tst_qcoapinternalrequest.cpp
@@ -235,7 +235,7 @@ void tst_QCoapInternalRequest::urlOptions()
     QFETCH(QString, url);
     QFETCH(QList<QCoapOption>, options);
 
-    const QCoapRequest request(url);
+    const QCoapRequest request(QUrl{url});
     const QCoapInternalRequest internalRequest(request);
 
     auto requestOptions = internalRequest.message()->options();
@@ -264,7 +264,7 @@ void tst_QCoapInternalRequest::invalidUrls_data()
 void tst_QCoapInternalRequest::invalidUrls()
 {
     QFETCH(QString, url);
-    const QCoapRequest request(url);
+    const QCoapRequest request(QUrl{url});
     const QCoapInternalRequest internalRequest(request);
 
     QVERIFY(!internalRequest.isValid());
@@ -288,7 +288,7 @@ void tst_QCoapInternalRequest::isMulticast()
     QFETCH(QString, url);
     QFETCH(bool, result);
 
-    const QCoapRequest request(url);
+    const QCoapRequest request(QUrl{url});
     const QCoapInternalRequest internalRequest(request);
     QCOMPARE(internalRequest.isMulticast(), result);
 }
diff --git a/tests/auto/qcoapqudpconnection/tst_qcoapqudpconnection.cpp b/tests/auto/qcoapqudpconnection/tst_qcoapqudpconnection.cpp
index 491ae53..37ff3c1 100644
--- a/tests/auto/qcoapqudpconnection/tst_qcoapqudpconnection.cpp
+++ b/tests/auto/qcoapqudpconnection/tst_qcoapqudpconnection.cpp
@@ -50,7 +50,7 @@ public:
 void tst_QCoapQUdpConnection::initTestCase()
 {
 #if defined(COAP_TEST_SERVER_IP) || defined(QT_TEST_SERVER)
-    QVERIFY2(waitForHost(testServerHost()), "Failed to connect to Californium plugtest server.");
+    QVERIFY2(waitForHost(QUrl{testServerHost()}), "Failed to connect to Californium plugtest server.");
 #endif
 }
 
@@ -164,7 +164,7 @@ void tst_QCoapQUdpConnection::sendRequest()
     QSignalSpy spyConnectionReadyRead(&connection, &QCoapQUdpConnection::readyRead);
 
     QCoapRequest request =
-            QCoapRequestPrivate::createRequest(QCoapRequest(protocol + host + path), method);
+            QCoapRequestPrivate::createRequest(QCoapRequest(QUrl{protocol + host + path}), method);
     request.setMessageId(24806);
     request.setToken(QByteArray("abcd"));
     QVERIFY(connection.socket() != nullptr);