diff --git a/src/util/externalcommandhelper.cpp b/src/util/externalcommandhelper.cpp
--- a/src/util/externalcommandhelper.cpp
+++ b/src/util/externalcommandhelper.cpp
@@ -90,7 +90,7 @@
 */
 quint64 ExternalCommandHelper::getNonce()
 {
-    quint64 nonce = m_Generator.generate();
+    const quint64 nonce = m_Generator.generate();
     m_Nonces.insert(nonce);
     return nonce;
 }
@@ -145,7 +145,7 @@
         return false;
     }
 
-    if (device.write(buffer) != buffer.size()) {
+    if (!device.write(buffer)) {
         qCritical() << xi18n("Could not write to device <filename>%1</filename>.", targetDevice);
         return false;
     }