diff --git a/FL/Fl_Device.H b/FL/Fl_Device.H
index 31d27c92f..b2403f9b1 100644
--- a/FL/Fl_Device.H
+++ b/FL/Fl_Device.H
@@ -15,6 +15,7 @@
 #include <stdio.h>
 #endif
 
+class Fl_Widget;
 class Fl_Image;
 class Fl_RGB_Image;
 class Fl_Pixmap;