diff -rupN --no-dereference gmsh-4.12.2-source/src/fltk/helpWindow.cpp gmsh-4.12.2-source-new/src/fltk/helpWindow.cpp
--- gmsh-4.12.2-source/src/fltk/helpWindow.cpp	2024-01-27 23:09:40.529174116 +0100
+++ gmsh-4.12.2-source-new/src/fltk/helpWindow.cpp	2024-01-27 23:09:41.096173209 +0100
@@ -3,6 +3,12 @@
 // See the LICENSE.txt file in the Gmsh root directory for license information.
 // Please report all issues on https://gitlab.onelab.info/gmsh/gmsh/issues.
 
+#include "GmshConfig.h"
+
+#if defined(HAVE_MED)
+#include <med/med.h>
+#endif
+
 #include <sstream>
 #include <algorithm>
 #include <string>
@@ -11,7 +17,6 @@
 #include <FL/Fl_Check_Button.H>
 #include <FL/Fl_Input.H>
 #include <FL/Fl_Color_Chooser.H>
-#include "GmshConfig.h"
 #include "FlGui.h"
 #include "inputValue.h"
 #include "helpWindow.h"