diff -Naur wmmaiload-2.3.0.orig/wmmaiload-config/main.c wmmaiload-2.3.0/wmmaiload-config/main.c
--- wmmaiload-2.3.0.orig/wmmaiload-config/main.c	2005-07-13 21:51:28.000000000 +0200
+++ wmmaiload-2.3.0/wmmaiload-config/main.c	2020-12-20 22:04:03.170530520 +0100
@@ -11,6 +11,18 @@
 #include "mainwindow.h"
 #include "actions.h"
 
+int backlight;
+int update_interval;
+int boxnum;
+int check_delay;
+int switch_authorized;
+int run_once;
+int test_size;
+char *config_file;
+char *light_color;
+char *command;
+char *notif_cmd;
+MailBox *mboxes;
 
 void Usage ()
 {
diff -Naur wmmaiload-2.3.0.orig/wmmaiload-config/mainwindow.c wmmaiload-2.3.0/wmmaiload-config/mainwindow.c
--- wmmaiload-2.3.0.orig/wmmaiload-config/mainwindow.c	2009-02-23 03:58:00.000000000 +0100
+++ wmmaiload-2.3.0/wmmaiload-config/mainwindow.c	2020-12-20 22:05:14.978622375 +0100
@@ -9,6 +9,19 @@
 #include "mainwindow.h"
 #include "actions.h"
 
+GtkWidget *application;
+GtkWidget *filelist;
+GtkWidget *wid_backlight;
+GtkWidget *wid_blink;
+GtkWidget *wid_interval;
+GtkWidget *wid_checkdelay;
+GtkWidget *wid_color;
+GtkWidget *wid_command;
+GtkWidget *wid_notify;
+GtkWidget *wid_runonce;
+GtkWidget *wid_testsize;
+
+int selected_row;
 
 static GtkWidget *b_edit;
 static GtkWidget *b_set;
diff -Naur wmmaiload-2.3.0.orig/wmmaiload-config/mainwindow.h wmmaiload-2.3.0/wmmaiload-config/mainwindow.h
--- wmmaiload-2.3.0.orig/wmmaiload-config/mainwindow.h	2005-07-07 20:54:17.000000000 +0200
+++ wmmaiload-2.3.0/wmmaiload-config/mainwindow.h	2020-12-20 22:05:14.978622375 +0100
@@ -7,19 +7,19 @@
 
 #include <gtk/gtk.h>
 
-GtkWidget *application;
-GtkWidget *filelist;
-GtkWidget *wid_backlight;
-GtkWidget *wid_blink;
-GtkWidget *wid_interval;
-GtkWidget *wid_checkdelay;
-GtkWidget *wid_color;
-GtkWidget *wid_command;
-GtkWidget *wid_notify;
-GtkWidget *wid_runonce;
-GtkWidget *wid_testsize;
+extern GtkWidget *application;
+extern GtkWidget *filelist;
+extern GtkWidget *wid_backlight;
+extern GtkWidget *wid_blink;
+extern GtkWidget *wid_interval;
+extern GtkWidget *wid_checkdelay;
+extern GtkWidget *wid_color;
+extern GtkWidget *wid_command;
+extern GtkWidget *wid_notify;
+extern GtkWidget *wid_runonce;
+extern GtkWidget *wid_testsize;
 
-int selected_row;
+extern int selected_row;
 
 gint list_unsel_cb (GtkCList *clist,
                     gint row,
diff -Naur wmmaiload-2.3.0.orig/wmmaiload-config/variables.h wmmaiload-2.3.0/wmmaiload-config/variables.h
--- wmmaiload-2.3.0.orig/wmmaiload-config/variables.h	2005-07-07 20:54:17.000000000 +0200
+++ wmmaiload-2.3.0/wmmaiload-config/variables.h	2020-12-20 22:04:03.170530520 +0100
@@ -7,17 +7,17 @@
 
 #include "defines.h"
 
-int backlight;
-int update_interval;
-int boxnum;
-int check_delay;
-int switch_authorized;
-int run_once;
-int test_size;
-char *config_file;
-char *light_color;
-char *command;
-char *notif_cmd;
-MailBox *mboxes;
+extern int backlight;
+extern int update_interval;
+extern int boxnum;
+extern int check_delay;
+extern int switch_authorized;
+extern int run_once;
+extern int test_size;
+extern char *config_file;
+extern char *light_color;
+extern char *command;
+extern char *notif_cmd;
+extern MailBox *mboxes;
 
 #endif