diff --git a/sdk/libraries/core/utils/SliderSpinBoxWidget.h b/sdk/libraries/core/utils/SliderSpinBoxWidget.h
index 6960da6aa173b0448b1a0b090a1af962067a52bf..c0edade6fcbb2fb127e28c66582fbcf6c64721b9 100644
--- a/sdk/libraries/core/utils/SliderSpinBoxWidget.h
+++ b/sdk/libraries/core/utils/SliderSpinBoxWidget.h
@@ -26,6 +26,9 @@
 #ifndef SLIDER_SPIN_BOX_WIDGET_H
 #define SLIDER_SPIN_BOX_WIDGET_H
 
+ // -- Core stuff
+#include "CamiTKAPI.h"
+
 // -- QT stuff
 #include <QSpinBox>
 #include <QSlider>
@@ -39,7 +42,7 @@ namespace camitk {
   * A utility class to have QSpinBox and QSlider synchronized.
   * see for example InteractiveViewer (when it is used as 2D viewer)
   */
-class SliderSpinBoxWidget : public QWidget {
+class CAMITK_API SliderSpinBoxWidget : public QWidget {
     Q_OBJECT
 
 public:
diff --git a/sdk/libraries/core/viewer/InteractiveViewer.h b/sdk/libraries/core/viewer/InteractiveViewer.h
index c9a041da38a37f39cc9a7abbf6b984b5a59685ed..2e6211414c22af0f375bc02499f155666bfe4075 100644
--- a/sdk/libraries/core/viewer/InteractiveViewer.h
+++ b/sdk/libraries/core/viewer/InteractiveViewer.h
@@ -66,7 +66,7 @@ class Property;
 using vtkSmartPointerCamera = vtkSmartPointer<vtkCamera>;
 
 /// InteractiveViewerFrame is just a QFrame that delegates all key events to its InteractiveViewer
-class InteractiveViewerFrame : public QFrame {
+class CAMITK_API InteractiveViewerFrame : public QFrame {
 public:
     /// default constructor
     InteractiveViewerFrame(QWidget* parent, InteractiveViewer* s3D) : QFrame(parent), myInteractiveViewer(s3D) {}