diff --git a/config.tests/unix/sctp/sctp.cpp b/config.tests/unix/sctp/sctp.cpp
index 40d7bb1bcb..61c33d5fc5 100644
--- a/config.tests/unix/sctp/sctp.cpp
+++ b/config.tests/unix/sctp/sctp.cpp
@@ -37,8 +37,10 @@
 **
 ****************************************************************************/
 
-/* Sample program for configure to test for SCTP sockets support
-on target platforms. */
+/*
+   Sample program for configure to test for SCTP sockets support
+   on target platforms.
+*/
 
 #include <sys/types.h>
 #include <sys/socket.h>
diff --git a/src/network/kernel/qnetworkproxy_win.cpp b/src/network/kernel/qnetworkproxy_win.cpp
index c022c718cf..949f9fe12b 100644
--- a/src/network/kernel/qnetworkproxy_win.cpp
+++ b/src/network/kernel/qnetworkproxy_win.cpp
@@ -288,7 +288,8 @@ static QList<QNetworkProxy> parseServerList(const QNetworkProxyQuery &query, con
     QHash<QString, QNetworkProxy> taggedProxies;
     const QString requiredTag = query.protocolTag();
     // windows tags are only for clients
-    bool checkTags = !requiredTag.isEmpty() && query.queryType() != QNetworkProxyQuery::TcpServer
+    bool checkTags = !requiredTag.isEmpty()
+            && query.queryType() != QNetworkProxyQuery::TcpServer
             && query.queryType() != QNetworkProxyQuery::SctpServer;
     for (const QString &entry : proxyList) {
         int server = 0;
diff --git a/src/network/socket/qnativesocketengine_unix.cpp b/src/network/socket/qnativesocketengine_unix.cpp
index 2a9d600630..d7d7dad8e7 100644
--- a/src/network/socket/qnativesocketengine_unix.cpp
+++ b/src/network/socket/qnativesocketengine_unix.cpp
@@ -915,7 +915,7 @@ qint64 QNativeSocketEnginePrivate::nativeReceiveDatagram(char *data, qint64 maxS
 
     if (recvResult == -1) {
         switch (errno) {
-#if EWOULDBLOCK-0 && EWOULDBLOCK != EAGAIN
+#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
         case EWOULDBLOCK:
 #endif
         case EAGAIN:
@@ -1105,7 +1105,7 @@ qint64 QNativeSocketEnginePrivate::nativeSendDatagram(const char *data, qint64 l
 
     if (sentBytes < 0) {
         switch (errno) {
-#if EWOULDBLOCK-0 && EWOULDBLOCK != EAGAIN
+#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
         case EWOULDBLOCK:
 #endif
         case EAGAIN:
diff --git a/src/network/socket/qsctpsocket.cpp b/src/network/socket/qsctpsocket.cpp
index 9ab241f9ab..f65ffa765d 100644
--- a/src/network/socket/qsctpsocket.cpp
+++ b/src/network/socket/qsctpsocket.cpp
@@ -162,8 +162,12 @@ bool QSctpSocketPrivate::canReadNotification()
         do {
             // Determine the size of the pending datagram.
             qint64 bytesToRead = socketEngine->bytesAvailable();
-            if (bytesToRead == 0)
+            if (bytesToRead == 0) {
+                // As a corner case, if we can't determine the size of the pending datagram,
+                // try to read 4K of data from the socket. Subsequent ::recvmsg call either
+                // fails or returns the actual length of the datagram.
                 bytesToRead = 4096;
+            }
 
             Q_ASSERT((datagramSize + int(bytesToRead)) < MaxByteArraySize);
             incomingDatagram.resize(datagramSize + int(bytesToRead));
@@ -479,7 +483,7 @@ QNetworkDatagram QSctpSocket::readDatagram()
     }
 
     if (d->currentReadChannel >= d->readHeaders.size()
-        || (d->readHeaders[d->currentReadChannel].size() == 0)) {
+        || d->readHeaders[d->currentReadChannel].size() == 0) {
         Q_ASSERT(d->buffer.isEmpty());
         return QNetworkDatagram();
     }
diff --git a/tests/auto/network/socket/qsctpsocket/tst_qsctpsocket.cpp b/tests/auto/network/socket/qsctpsocket/tst_qsctpsocket.cpp
index 70297f8cc4..fc976fbd0d 100644
--- a/tests/auto/network/socket/qsctpsocket/tst_qsctpsocket.cpp
+++ b/tests/auto/network/socket/qsctpsocket/tst_qsctpsocket.cpp
@@ -118,13 +118,13 @@ void tst_QSctpSocket::constructing()
 
     char c;
     QCOMPARE(socket.getChar(&c), false);
-    QCOMPARE((int) socket.bytesAvailable(), 0);
+    QCOMPARE(socket.bytesAvailable(), Q_INT64_C(0));
     QCOMPARE(socket.canReadLine(), false);
     QCOMPARE(socket.readLine(), QByteArray());
-    QCOMPARE(socket.socketDescriptor(), (qintptr)-1);
-    QCOMPARE((int) socket.localPort(), 0);
+    QCOMPARE(socket.socketDescriptor(), qintptr(-1));
+    QCOMPARE(int(socket.localPort()), 0);
     QVERIFY(socket.localAddress() == QHostAddress());
-    QCOMPARE((int) socket.peerPort(), 0);
+    QCOMPARE(int(socket.peerPort()), 0);
     QVERIFY(socket.peerAddress() == QHostAddress());
     QCOMPARE(socket.error(), QAbstractSocket::UnknownSocketError);
     QCOMPARE(socket.errorString(), QString("Unknown error"));
@@ -139,11 +139,11 @@ void tst_QSctpSocket::bind_data()
 
     // iterate all interfaces, add all addresses on them as test data
     QList<QNetworkInterface> interfaces = QNetworkInterface::allInterfaces();
-    foreach (const QNetworkInterface &interface, interfaces) {
+    for (const QNetworkInterface &interface : interfaces) {
         if (!interface.isValid())
             continue;
 
-        foreach (const QNetworkAddressEntry &entry, interface.addressEntries()) {
+        for (const QNetworkAddressEntry &entry : interface.addressEntries()) {
             if (entry.ip().isInSubnet(QHostAddress::parseSubnet("fe80::/10"))
                 || entry.ip().isInSubnet(QHostAddress::parseSubnet("169.254/16")))
                 continue; // link-local bind will fail, at least on Linux, so skip it.
@@ -178,11 +178,10 @@ void tst_QSctpSocket::bind()
     QSctpSocket socket;
     qDebug() << "Binding " << addr;
 
-    if (successExpected) {
+    if (successExpected)
         QVERIFY2(socket.bind(addr), qPrintable(socket.errorString()));
-    } else {
+    else
         QVERIFY(!socket.bind(addr));
-    }
 
     QCOMPARE(socket.localAddress(), expectedLocalAddress);
 }
@@ -191,9 +190,9 @@ void tst_QSctpSocket::bind()
 void tst_QSctpSocket::setInvalidSocketDescriptor()
 {
     QSctpSocket socket;
-    QCOMPARE(socket.socketDescriptor(), (qintptr)INVALID_SOCKET);
+    QCOMPARE(socket.socketDescriptor(), qintptr(INVALID_SOCKET));
     QVERIFY(!socket.setSocketDescriptor(-5, QAbstractSocket::UnconnectedState));
-    QCOMPARE(socket.socketDescriptor(), (qintptr)INVALID_SOCKET);
+    QCOMPARE(socket.socketDescriptor(), qintptr(INVALID_SOCKET));
 
     QCOMPARE(socket.error(), QAbstractSocket::UnsupportedSocketOperationError);
 }
@@ -211,7 +210,7 @@ void tst_QSctpSocket::setSocketDescriptor()
     QVERIFY(sock != INVALID_SOCKET);
     QSctpSocket socket;
     QVERIFY(socket.setSocketDescriptor(sock, QAbstractSocket::UnconnectedState));
-    QCOMPARE(socket.socketDescriptor(), (qintptr)sock);
+    QCOMPARE(socket.socketDescriptor(), qintptr(sock));
     QCOMPARE(socket.readChannelCount(), 0);
     QCOMPARE(socket.writeChannelCount(), 0);
 
@@ -237,7 +236,7 @@ void tst_QSctpSocket::socketDescriptor()
 
     QVERIFY(server.listen());
 
-    QCOMPARE(socket.socketDescriptor(), (qintptr)INVALID_SOCKET);
+    QCOMPARE(socket.socketDescriptor(), qintptr(INVALID_SOCKET));
     socket.connectToHost(QHostAddress::LocalHost, server.serverPort());
     QVERIFY(server.waitForNewConnection(3000));
     if (socket.state() != QAbstractSocket::ConnectedState) {