diff --git a/UpdatePTUDevCtrl/process/command.cpp b/UpdatePTUDevCtrl/process/command.cpp
index 8e0cf68..ab8f40d 100644
--- a/UpdatePTUDevCtrl/process/command.cpp
+++ b/UpdatePTUDevCtrl/process/command.cpp
@@ -5,6 +5,7 @@
 #include <QDir>
 #include <QRegularExpression>
 #include <QDateTime>
+#include <QMutexLocker>
 
 Command::Command(QString const &command, int start_timeout, int finish_timeout)
     : m_command(command.trimmed())
@@ -14,14 +15,23 @@ Command::Command(QString const &command, int start_timeout, int finish_timeout)
     , m_exitCode(-1) {
 }
 
-QString Command::getCommandResult() const {
-    return m_commandResult;
+QString Command::getCommandResult(bool reset) const {
+    QMutexLocker locker(&m_mtx);
+
+    if (reset == false) {
+        return m_commandResult;
+    }
+
+    QString commandResult = m_commandResult;
+    m_commandResult.clear();
+
+    return commandResult;
 }
 
 void Command::readyReadStandardOutput() {
+    QMutexLocker locker(&m_mtx);
     QProcess *p = (QProcess *)sender();
     m_commandResult += p->readAllStandardOutput();
-    // qCritical() << m_commandResult;
 }
 
 void Command::readyReadStandardError() {
@@ -35,6 +45,7 @@ void Command::finished(int /*exitCode*/, QProcess::ExitStatus /*exitStatus*/) {
     // read all remaining data sent to the process, just in case
     QString d = p->readAllStandardOutput();
     if (!d.isEmpty()) {
+        QMutexLocker locker(&m_mtx);
         m_commandResult += d;
     }
     disconnect(p, SIGNAL(finished(int,QProcess::ExitStatus)), this, SLOT(readyReadStandardOutput()));
diff --git a/UpdatePTUDevCtrl/process/command.h b/UpdatePTUDevCtrl/process/command.h
index bc796ee..460f935 100644
--- a/UpdatePTUDevCtrl/process/command.h
+++ b/UpdatePTUDevCtrl/process/command.h
@@ -7,22 +7,24 @@
 #include <QString>
 #include <QStringList>
 #include <QProcess>
+#include <QMutex>
 
 
 class Command : public QObject {
     Q_OBJECT
 
     QString m_command;
-    QString m_commandResult;
+    mutable QString m_commandResult;
     int m_waitForStartTimeout;
     int m_waitForFinishTimeout;
     int m_exitCode;
+    mutable QMutex m_mtx;
 public:
     explicit Command(QString const &command,
                      int start_timeout = 100000,
                      int finish_timeout = 100000);
 
-    QString getCommandResult() const;
+    QString getCommandResult(bool reset = false) const;
     QString command() const { return m_command; }
 
     bool execute(QString workingDirectory, QStringList args = QStringList());