diff --git a/include/wx/display.h b/include/wx/display.h
index 002ce99ced..d209557a66 100644
--- a/include/wx/display.h
+++ b/include/wx/display.h
@@ -28,7 +28,7 @@
 class WXDLLEXPORT wxWindow;
 class WXDLLEXPORT wxPoint;
 class WXDLLEXPORT wxRect;
-class WXDLLEXPORT wxString;
+class WXDLLIMPEXP_BASE wxString;
 
 class WXDLLEXPORT wxDisplayFactory;
 class WXDLLEXPORT wxDisplayImpl;
diff --git a/include/wx/os2/private.h b/include/wx/os2/private.h
index c8064639aa..40d7865e3e 100644
--- a/include/wx/os2/private.h
+++ b/include/wx/os2/private.h
@@ -79,7 +79,7 @@
 
 class WXDLLEXPORT wxFont;
 class WXDLLEXPORT wxWindow;
-class WXDLLEXPORT wxString;
+class WXDLLIMPEXP_BASE wxString;
 class WXDLLEXPORT wxBitmap;
 
 // ---------------------------------------------------------------------------