diff --git a/src/device.h b/src/device.h
--- a/src/device.h
+++ b/src/device.h
@@ -66,9 +66,6 @@
     virtual bool isDefault() const = 0;
     virtual void setDefault(bool enable) = 0;
 
-    template <typename PAInfo>
-    void updateDevice(const PAInfo *info);
-
 Q_SIGNALS:
     void stateChanged();
     void nameChanged();
@@ -84,7 +81,8 @@
     DevicePrivate *d;
 
 private:
-    State stateFromPaState(int value) const;
+    friend class SinkPrivate;
+    friend class SourcePrivate;
 };
 
 } // PulseAudioQt
diff --git a/src/device.cpp b/src/device.cpp
--- a/src/device.cpp
+++ b/src/device.cpp
@@ -69,19 +69,19 @@
 {
 }
 
-Device::State Device::stateFromPaState(int value) const
+Device::State DevicePrivate::stateFromPaState(int value) const
 {
     switch (value) {
     case -1: // PA_X_INVALID_STATE
-        return InvalidState;
+        return Device::InvalidState;
     case 0:  // PA_X_RUNNING
-        return RunningState;
+        return Device::RunningState;
     case 1:  // PA_X_IDLE
-        return IdleState;
+        return Device::IdleState;
     case 2:  // PA_X_SUSPENDED
-        return SuspendedState;
+        return Device::SuspendedState;
     default:
-        return UnknownState;
+        return Device::UnknownState;
     }
 }
 
diff --git a/src/device_p.h b/src/device_p.h
--- a/src/device_p.h
+++ b/src/device_p.h
@@ -47,56 +47,58 @@
     quint32 m_activePortIndex = -1;
     Device::State m_state = Device::UnknownState;
 
-};
+    Device::State stateFromPaState(int value) const;
 
-template <typename PAInfo>
-void Device::updateDevice(const PAInfo *info)
-{
-    updateVolumeObject(info);
+    template <typename PAInfo>
+    void updateDevice(const PAInfo *info)
+    {
+        q->updateVolumeObject(info);
 
-    if (d->m_name != info->name) {
-        d->m_name = info->name;
-        Q_EMIT nameChanged();
-    }
-    if (d->m_description != info->description) {
-        d->m_description = info->description;
-        Q_EMIT descriptionChanged();
-    }
-    const char *form_factor = pa_proplist_gets(info->proplist, PA_PROP_DEVICE_FORM_FACTOR);
-    if (form_factor) {
-        QString formFactor = QString::fromUtf8(form_factor);
-        if (d->m_formFactor != formFactor) {
-            d->m_formFactor = formFactor;
-            Q_EMIT formFactorChanged();
+        if (m_name != info->name) {
+            m_name = info->name;
+            Q_EMIT q->nameChanged();
+        }
+        if (m_description != info->description) {
+            m_description = info->description;
+            Q_EMIT q->descriptionChanged();
+        }
+        const char *form_factor = pa_proplist_gets(info->proplist, PA_PROP_DEVICE_FORM_FACTOR);
+        if (form_factor) {
+            QString formFactor = QString::fromUtf8(form_factor);
+            if (m_formFactor != formFactor) {
+                m_formFactor = formFactor;
+                Q_EMIT q->formFactorChanged();
+            }
         }
-    }
 
-    d->m_cardIndex = info->card;
-    Q_EMIT cardIndexChanged();
-
-    // TODO: this rebuilds the entire port list on every update. would be
-    // nicer if it actually removed what needs removing updates what needs
-    // updating and adds what needs adding. Alas, this is a tad more
-    // involved.
-    qDeleteAll(d->m_ports);
-    d->m_ports.clear();
-    for (auto **ports = info->ports; ports && *ports != nullptr; ++ports) {
-        Port *port = new Port(this);
-        port->setInfo(*ports);
-        d->m_ports.append(port);
-        if (info->active_port == *ports) {
-            d->m_activePortIndex = d->m_ports.length() - 1;
+        m_cardIndex = info->card;
+        Q_EMIT q->cardIndexChanged();
+
+        // TODO: this rebuilds the entire port list on every update. would be
+        // nicer if it actually removed what needs removing updates what needs
+        // updating and adds what needs adding. Alas, this is a tad more
+        // involved.
+        qDeleteAll(m_ports);
+        m_ports.clear();
+        for (auto **ports = info->ports; ports && *ports != nullptr; ++ports) {
+            Port *port = new Port(q);
+            port->setInfo(*ports);
+            m_ports.append(port);
+            if (info->active_port == *ports) {
+                m_activePortIndex = m_ports.length() - 1;
+            }
         }
-    }
-    Q_EMIT portsChanged();
-    Q_EMIT activePortIndexChanged();
+        Q_EMIT q->portsChanged();
+        Q_EMIT q->activePortIndexChanged();
 
-    State infoState = stateFromPaState(info->state);
-    if (infoState != d->m_state) {
-        d->m_state = infoState;
-        Q_EMIT stateChanged();
+        Device::State infoState = stateFromPaState(info->state);
+        if (infoState != m_state) {
+            m_state = infoState;
+            Q_EMIT q->stateChanged();
+        }
     }
-}
+
+    };
 
 } // namespace PulseAudioQt
 
diff --git a/src/port.h b/src/port.h
--- a/src/port.h
+++ b/src/port.h
@@ -41,7 +41,7 @@
     explicit Port(QObject *parent);
     class PortPrivate *const d;
 
-    friend class Device;
+    friend class DevicePrivate;
 };
 
 } // PulseAudioQt
diff --git a/src/sink.cpp b/src/sink.cpp
--- a/src/sink.cpp
+++ b/src/sink.cpp
@@ -50,7 +50,7 @@
 
 void SinkPrivate::update(const pa_sink_info *info)
 {
-    q->updateDevice(info);
+    q->Device::d->updateDevice(info);
 }
 
 void Sink::setVolume(qint64 volume)
diff --git a/src/source.cpp b/src/source.cpp
--- a/src/source.cpp
+++ b/src/source.cpp
@@ -44,7 +44,7 @@
 
 void SourcePrivate::update(const pa_source_info *info)
 {
-    q->updateDevice(info);
+    q->Device::d->updateDevice(info);
 }
 
 void Source::setVolume(qint64 volume)
diff --git a/src/volumeobject.h b/src/volumeobject.h
--- a/src/volumeobject.h
+++ b/src/volumeobject.h
@@ -67,6 +67,7 @@
     void updateVolumeObject(PAInfo *info);
 
     class VolumeObjectPrivate *const d;
+    friend class DevicePrivate;
 };
 
 } // PulseAudioQt