diff --git a/src/plugins/qmldesigner/styledoutputpaneplaceholder.cpp b/src/plugins/qmldesigner/styledoutputpaneplaceholder.cpp
index b1169edfc1ec5807e74014588a26a1b6c70d03ff..540f122049b939b1971eb25dcd00a8b6a3fa3681 100644
--- a/src/plugins/qmldesigner/styledoutputpaneplaceholder.cpp
+++ b/src/plugins/qmldesigner/styledoutputpaneplaceholder.cpp
@@ -33,9 +33,12 @@
 
 #include <QChildEvent>
 #include <QTabWidget>
-#include <QDebug>
 
-StyledOutputpanePlaceHolder::StyledOutputpanePlaceHolder(Core::IMode *mode, QSplitter *parent) : Core::OutputPanePlaceHolder(mode, parent)
+namespace QmlDesigner {
+namespace Internal {
+
+StyledOutputpanePlaceHolder::StyledOutputpanePlaceHolder(Core::IMode *mode, QSplitter *parent)
+    : Core::OutputPanePlaceHolder(mode, parent)
 {
     QByteArray sheet = Utils::FileReader::fetchQrc(":/qmldesigner/outputpane-style.css");
     sheet += Utils::FileReader::fetchQrc(":/qmldesigner/scrollbar.css");
@@ -65,3 +68,6 @@ void StyledOutputpanePlaceHolder::childEvent(QChildEvent *event)
         }
     }
 }
+
+} // namespace Internal
+} // namespace QmlDesigner
diff --git a/src/plugins/qmldesigner/styledoutputpaneplaceholder.h b/src/plugins/qmldesigner/styledoutputpaneplaceholder.h
index 5a694ccc8de2ea997fd84c90b056c8bd5b172d18..1aa773074a851758a37210231d929df5a798b635 100644
--- a/src/plugins/qmldesigner/styledoutputpaneplaceholder.h
+++ b/src/plugins/qmldesigner/styledoutputpaneplaceholder.h
@@ -32,7 +32,8 @@
 
 #include <coreplugin/outputpane.h>
 
-QT_FORWARD_DECLARE_CLASS(QChildEvent)
+namespace QmlDesigner {
+namespace Internal {
 
 class StyledOutputpanePlaceHolder : public Core::OutputPanePlaceHolder
 {
@@ -41,9 +42,12 @@ public:
 
 protected:
     void childEvent(QChildEvent *event);
+
 private:
     QString m_customStylesheet;
-
 };
 
+} // namespace Internal
+} // namespace QmlDesigner
+
 #endif // STYLEDOUTPUTPANEPLACEHOLDER_H