diff --git a/extensions.cpp b/extensions.cpp
index a56fdf423..960c68bd5 100644
--- a/extensions.cpp
+++ b/extensions.cpp
@@ -13,6 +13,9 @@
 // local includes
 #include "part.h"
 
+namespace Okular
+{
+
 /*
  * BrowserExtension class
  */
@@ -114,6 +117,7 @@ void OkularLiveConnectExtension::postMessage( const QStringList &args )
           "{ this.messageHandler.onMessage(" + arrayarg + ") }" );
 }
 
+}
 
 #include "extensions.moc"
 
diff --git a/extensions.h b/extensions.h
index d99a038e9..dcd5c1cb8 100644
--- a/extensions.h
+++ b/extensions.h
@@ -13,6 +13,9 @@
 
 #include <kparts/browserextension.h>
 
+namespace Okular
+{
+
 class Part;
 
 class BrowserExtension : public KParts::BrowserExtension
@@ -51,6 +54,9 @@ class OkularLiveConnectExtension : public KParts::LiveConnectExtension
         bool m_inEval;
         QString m_evalRes;
 };
+
+}
+
 #endif
 
 /* kate: replace-tabs on; indent-width 4; */
diff --git a/part.cpp b/part.cpp
index d426d4d5b..ede7935fc 100644
--- a/part.cpp
+++ b/part.cpp
@@ -143,7 +143,7 @@ class FileKeeper
         std::FILE * m_handle;
 };
 
-K_PLUGIN_FACTORY( okularPartFactory, registerPlugin< Part >(); )
+K_PLUGIN_FACTORY( okularPartFactory, registerPlugin< Okular::Part >(); )
 K_EXPORT_PLUGIN( okularPartFactory( okularAboutData( "okular", I18N_NOOP( "Okular" ) ) ) )
 
 static QAction* actionForExportFormat( const Okular::ExportFormat& format, QObject *parent = 0 )
@@ -183,29 +183,29 @@ static QString compressedMimeFor( const QString& mime_to_check )
     return QString();
 }
 
-static Part::EmbedMode detectEmbedMode( QWidget *parentWidget, QObject *parent, const QVariantList &args )
+static Okular::Part::EmbedMode detectEmbedMode( QWidget *parentWidget, QObject *parent, const QVariantList &args )
 {
     Q_UNUSED( parentWidget );
 
     if ( parent
          && ( parent->objectName() == QLatin1String( "okular::Shell" )
               || parent->objectName() == QLatin1String( "okular/okular__Shell" ) ) )
-        return Part::NativeShellMode;
+        return Okular::Part::NativeShellMode;
 
     if ( parent
          && ( QByteArray( "KHTMLPart" ) == parent->metaObject()->className() ) )
-        return Part::KHTMLPartMode;
+        return Okular::Part::KHTMLPartMode;
 
     Q_FOREACH ( const QVariant &arg, args )
     {
         if ( arg.type() == QVariant::String )
         {
             if ( arg.toString() == QLatin1String( "Print/Preview" ) )
-                return Part::PrintPreviewMode;
+                return Okular::Part::PrintPreviewMode;
         }
     }
 
-    return Part::UnknownEmbedMode;
+    return Okular::Part::UnknownEmbedMode;
 }
 
 #undef OKULAR_KEEP_FILE_OPEN
@@ -218,6 +218,9 @@ static bool keepFileOpen()
 }
 #endif
 
+namespace Okular
+{
+
 Part::Part(QWidget *parentWidget,
 QObject *parent,
 const QVariantList &args )
@@ -2167,6 +2170,7 @@ void Part::updateAboutBackendAction()
     }
 }
 
+} // namespace Okular
 
 #include "part.moc"
 
diff --git a/part.h b/part.h
index 58f5cb186..b55df610b 100644
--- a/part.h
+++ b/part.h
@@ -59,10 +59,9 @@ class BookmarkList;
 
 namespace Okular
 {
-class ExportFormat;
-}
 
 class BrowserExtension;
+class ExportFormat;
 
 /**
  * This is a "Part".  It that does all the real work in a KPart
@@ -274,6 +273,8 @@ class Part : public KParts::ReadOnlyPart, public Okular::DocumentObserver, publi
         void slotGeneratorPreferences();
 };
 
+}
+
 #endif
 
 /* kate: replace-tabs on; indent-width 4; */