diff --git a/Graphics/drawContext.cpp b/Graphics/drawContext.cpp
index 539b6ba8ec4b287832f8e7191724c514b670614f..e7e683ecb285c305a198b14e63f0f0aa286760f6 100644
--- a/Graphics/drawContext.cpp
+++ b/Graphics/drawContext.cpp
@@ -21,7 +21,7 @@
 #include "gl2ps.h"
 
 #if defined(HAVE_FLTK)
-#include <FL/Fl.h>
+#include <FL/Fl.H>
 #include <FL/Fl_JPEG_Image.H>
 #include <FL/Fl_PNG_Image.H>
 #include <FL/gl.h>