diff --git a/src/third-party/singleapplication/singleapplication.cpp b/src/third-party/singleapplication/singleapplication.cpp
index c74d6dbc..cdb90a4b 100644
--- a/src/third-party/singleapplication/singleapplication.cpp
+++ b/src/third-party/singleapplication/singleapplication.cpp
@@ -209,7 +209,7 @@ void SingleApplicationPrivate::connectToPrimary( int msecs, ConnectionType conne
         // Notify the parent that a new instance had been started;
         QByteArray initMsg;
         QDataStream writeStream(&initMsg, QIODevice::WriteOnly);
-        writeStream.setVersion(QDataStream::Qt_5_6);
+        writeStream.setVersion(QDataStream::Qt_5_2);
         writeStream << blockServerName.toLatin1();
         writeStream << static_cast<quint8>(connectionType);
         writeStream << instanceNumber;
@@ -278,7 +278,7 @@ void SingleApplicationPrivate::slotConnectionEstablished()
         QByteArray msgBytes = nextConnSocket->read(nextConnSocket->bytesAvailable() - static_cast<qint64>(sizeof(quint16)));
         QByteArray checksumBytes = nextConnSocket->read(sizeof(quint16));
         QDataStream readStream(msgBytes);
-        readStream.setVersion(QDataStream::Qt_5_6);
+        readStream.setVersion(QDataStream::Qt_5_2);
 
         // server name
         QByteArray latin1Name;
@@ -292,7 +292,7 @@ void SingleApplicationPrivate::slotConnectionEstablished()
         // checksum
         quint16 msgChecksum = 0;
         QDataStream checksumStream(checksumBytes);
-        checksumStream.setVersion(QDataStream::Qt_5_6);
+        checksumStream.setVersion(QDataStream::Qt_5_2);
         checksumStream >> msgChecksum;
 
         const quint16 actualChecksum = qChecksum(msgBytes.constData(), static_cast<quint32>(msgBytes.length()));