diff --git interfaces/viewerinterface.h interfaces/viewerinterface.h
index c3de2e9..1418c60 100644
--- interfaces/viewerinterface.h
+++ interfaces/viewerinterface.h
@@ -23,7 +23,7 @@ namespace Okular {
  * This interface can be used to control some more or less advanced features of a document
  * viewer.
  */
-class ViewerInterface
+class OKULAR_EXPORT ViewerInterface
 {
     public:
         virtual ~ViewerInterface() {}
diff --git kdocumentviewer.h kdocumentviewer.h
index 2f77610..360ed42 100644
--- kdocumentviewer.h
+++ kdocumentviewer.h
@@ -10,6 +10,8 @@
 #ifndef _KDOCUMENTVIEWER_H_
 #define _KDOCUMENTVIEWER_H_
 
+#include "core/okular_export.h"
+
 #include <QtCore/QStringList>
 
 class KUrl;
@@ -19,7 +21,7 @@ class KUrl;
  *
  * This interface describe briefly the basic functions of a document viewer.
  */
-class KDocumentViewer
+class OKULAR_EXPORT KDocumentViewer
 {
     public:
         virtual ~KDocumentViewer() {}