diff --git a/src/sink.cpp b/src/sink.cpp
index 37ca9c3..8058a8a 100644
--- a/src/sink.cpp
+++ b/src/sink.cpp
@@ -1,77 +1,77 @@
 /*
     Copyright 2014-2015 Harald Sitter <sitter@kde.org>
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 of the License, or (at your option) version 3, or any
     later version accepted by the membership of KDE e.V. (or its
     successor approved by the membership of KDE e.V.), which shall
     act as a proxy defined in Section 6 of version 3 of the license.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.
 
     You should have received a copy of the GNU Lesser General Public
     License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "sink.h"
 
 #include "context.h"
 #include "server.h"
 
 namespace QPulseAudio
 {
 
 Sink::Sink(QObject *parent)
     : Device(parent)
 {
     connect(context()->server(), &Server::defaultSinkChanged, this, &Sink::defaultChanged);
 }
 
 void Sink::update(const pa_sink_info *info)
 {
     updateDevice(info);
 }
 
 void Sink::setVolume(qint64 volume)
 {
     context()->setGenericVolume(index(), -1, volume, cvolume(), &pa_context_set_sink_volume_by_index);
 }
 
 void Sink::setMuted(bool muted)
 {
     context()->setGenericMute(m_index, muted, &pa_context_set_sink_mute_by_index);
 }
 
 void Sink::setActivePortIndex(quint32 port_index)
 {
     Port *port = qobject_cast<Port *>(ports().at(port_index));
     if (!port) {
         qCWarning(PLASMAPA) << "invalid port set request" << port_index;
         return;
     }
     context()->setGenericPort(index(), port->name(), &pa_context_set_sink_port_by_index);
 }
 
 void Sink::setChannelVolume(int channel, qint64 volume)
 {
     context()->setGenericVolume(index(), channel, volume, cvolume(), &pa_context_set_sink_volume_by_index);
 }
 
 bool Sink::isDefault() const
 {
     return context()->server()->defaultSink() == this;
 }
 
 void Sink::setDefault(bool enable)
 {
-    if (enable) {
+    if (!isDefault() && enable) {
         context()->server()->setDefaultSink(this);
     }
 }
 
 } // QPulseAudio
diff --git a/src/source.cpp b/src/source.cpp
index 21fb3ee..c010b5d 100644
--- a/src/source.cpp
+++ b/src/source.cpp
@@ -1,77 +1,77 @@
 /*
     Copyright 2014-2015 Harald Sitter <sitter@kde.org>
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 of the License, or (at your option) version 3, or any
     later version accepted by the membership of KDE e.V. (or its
     successor approved by the membership of KDE e.V.), which shall
     act as a proxy defined in Section 6 of version 3 of the license.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.
 
     You should have received a copy of the GNU Lesser General Public
     License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "source.h"
 
 #include "context.h"
 #include "server.h"
 
 namespace QPulseAudio
 {
 
 Source::Source(QObject *parent)
     : Device(parent)
 {
     connect(context()->server(), &Server::defaultSourceChanged, this, &Source::defaultChanged);
 }
 
 void Source::update(const pa_source_info *info)
 {
     updateDevice(info);
 }
 
 void Source::setVolume(qint64 volume)
 {
     context()->setGenericVolume(index(), -1, volume, cvolume(), &pa_context_set_source_volume_by_index);
 }
 
 void Source::setMuted(bool muted)
 {
     context()->setGenericMute(index(), muted, &pa_context_set_source_mute_by_index);
 }
 
 void Source::setActivePortIndex(quint32 port_index)
 {
     Port *port = qobject_cast<Port *>(ports().at(port_index));
     if (!port) {
         qCWarning(PLASMAPA) << "invalid port set request" << port_index;
         return;
     }
     context()->setGenericPort(index(), port->name(), &pa_context_set_source_port_by_index);
 }
 
 void Source::setChannelVolume(int channel, qint64 volume)
 {
     context()->setGenericVolume(index(), channel, volume, cvolume(), &pa_context_set_source_volume_by_index);
 }
 
 bool Source::isDefault() const
 {
     return context()->server()->defaultSource() == this;
 }
 
 void Source::setDefault(bool enable)
 {
-    if (enable) {
+    if (!isDefault() && enable) {
         context()->server()->setDefaultSource(this);
     }
 }
 
 } // QPulseAudio