diff --git a/src/backend/corebackendmanager.cpp b/src/backend/corebackendmanager.cpp
index 3f9b817..195bbf6 100644
--- a/src/backend/corebackendmanager.cpp
+++ b/src/backend/corebackendmanager.cpp
@@ -65,8 +65,6 @@ QVector<KPluginMetaData> CoreBackendManager::list() const
 
 void CoreBackendManager::startExternalCommandHelper()
 {
-    stopExternalCommandHelper();
-
     KAuth::Action action = KAuth::Action(QStringLiteral("org.kde.kpmcore.externalcommand.init"));
     action.setHelperId(QStringLiteral("org.kde.kpmcore.externalcommand"));
     action.setTimeout(10 * 24 * 3600 * 1000); // 10 days
diff --git a/src/util/externalcommand.cpp b/src/util/externalcommand.cpp
index c77ad36..533cde1 100644
--- a/src/util/externalcommand.cpp
+++ b/src/util/externalcommand.cpp
@@ -139,28 +139,14 @@ void ExternalCommand::setup(const QProcess::ProcessChannelMode processChannelMod
 //     connect(this, &ExternalCommand::readyReadStandardOutput, this, &ExternalCommand::onReadOutput);
 }
 
-/** Starts the external command.
+/** Executes the external command.
     @param timeout timeout to wait for the process to start
     @return true on success
 */
-
 bool ExternalCommand::start(int timeout)
 {
-//     this->moveToThread(CoreBackendManager::self()->kauthThread());
-//     QTimer::singleShot(0, this, &ExternalCommand::execute);
-//     QEventLoop loop;
-//     connect(this, &ExternalCommand::finished, &loop, &QEventLoop::quit);
-//     loop.exec();
-//     return true;
     Q_UNUSED(timeout)
-    execute();
-    return true;
-}
 
-/** Executes the external command in kauthThread() thread.
-*/
-void ExternalCommand::execute()
-{
     if (report()) {
         report()->setCommand(xi18nc("@info:status", "Command: %1 %2", command(), args().join(QStringLiteral(" "))));
     }
@@ -171,7 +157,7 @@ void ExternalCommand::execute()
 
     if (!QDBusConnection::systemBus().isConnected()) {
         qWarning() << "Could not connect to DBus system bus";
-        return;
+        return false;
     }
 
     QDBusInterface iface(QStringLiteral("org.kde.kpmcore.helperinterface"),
@@ -181,6 +167,7 @@ void ExternalCommand::execute()
 
     iface.setTimeout(10 * 24 * 3600 * 1000); // 10 days
 
+    bool rval = false;
     if (iface.isValid()) {
         QDBusPendingCall pcall = iface.asyncCall(QStringLiteral("start"),
                                                  CoreBackendManager::self()->Uuid(),
@@ -206,11 +193,13 @@ void ExternalCommand::execute()
             }
 
             emit finished();
+            rval = true;
         };
 
         connect(watcher, &QDBusPendingCallWatcher::finished, exitLoop);
         loop.exec();
     }
+    return rval;
 }
 
 bool ExternalCommand::write(const QByteArray& input)
diff --git a/src/util/externalcommand.h b/src/util/externalcommand.h
index 3acace8..01b02bf 100644
--- a/src/util/externalcommand.h
+++ b/src/util/externalcommand.h
@@ -93,8 +93,6 @@ public Q_SLOTS:
     void emitProgress(KJob*, unsigned long percent) { emit progress(percent); };
 
 protected:
-    void execute();
-
     void setExitCode(int i) {
         m_ExitCode = i;
     }
diff --git a/src/util/externalcommandhelper.cpp b/src/util/externalcommandhelper.cpp
index a4d9012..6b0ebaa 100644
--- a/src/util/externalcommandhelper.cpp
+++ b/src/util/externalcommandhelper.cpp
@@ -1,5 +1,5 @@
 /*************************************************************************
- *  Copyright (C) 2017 by Andrius Štikonas <andrius@stikonas.eu>         *
+ *  Copyright (C) 2017-2018 by Andrius Štikonas <andrius@stikonas.eu>    *
  *                                                                       *
  *  This program is free software; you can redistribute it and/or        *
  *  modify it under the terms of the GNU General Public License as       *
@@ -111,7 +111,8 @@ bool ExternalCommandHelper::writeData(const QString &targetDevice, const QByteAr
 
 bool ExternalCommandHelper::copyblocks(const QString& Uuid, const QString& sourceDevice, const qint64 sourceFirstByte, const qint64 sourceLength, const QString& targetDevice, const qint64 targetFirstByte, const qint64 blockSize)
 {
-    isCallerAuthorized(Uuid);
+    if (!isCallerAuthorized(Uuid))
+        return false;
 
     const qint64 blocksToCopy = sourceLength / blockSize;
     qint64 readOffset = sourceFirstByte;
@@ -194,8 +195,11 @@ bool ExternalCommandHelper::copyblocks(const QString& Uuid, const QString& sourc
 
 QVariantMap ExternalCommandHelper::start(const QString& Uuid, const QString& command, const QStringList& arguments, const QByteArray& input, const QStringList& environment)
 {
-    isCallerAuthorized(Uuid);
     QVariantMap reply;
+    if (!isCallerAuthorized(Uuid)) {
+        reply[QStringLiteral("success")] = false;
+        return reply;
+    }
 
 //     connect(&cmd, &QProcess::readyReadStandardOutput, this, &ExternalCommandHelper::onReadOutput);
 
@@ -223,7 +227,8 @@ bool ExternalCommandHelper::isCallerAuthorized(const QString& Uuid)
 
 void ExternalCommandHelper::exit(const QString& Uuid)
 {
-    isCallerAuthorized(Uuid);
+    if (!isCallerAuthorized(Uuid))
+        return;
     m_loop.exit();
 
     if (QDBusConnection::systemBus().unregisterService(QStringLiteral("org.kde.kpmcore.helperinterface")))