diff -Naur pasystray-0.8.2.orig/src/avahi.c pasystray-0.8.2/src/avahi.c
--- pasystray-0.8.2.orig/src/avahi.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/avahi.c	2026-01-09 15:20:12.787084671 +0200
@@ -107,7 +107,7 @@
                 avahi_strerror(avahi_client_errno(client)));
 }
 
-void avahi_destroy()
+void avahi_destroy(void)
 {
     if(sb)
         avahi_service_browser_free(sb);
diff -Naur pasystray-0.8.2.orig/src/avahi.h pasystray-0.8.2/src/avahi.h
--- pasystray-0.8.2.orig/src/avahi.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/avahi.h	2026-01-09 15:20:37.833950935 +0200
@@ -28,6 +28,6 @@
 
 void avahi_init(GMainLoop* loop);
 void avahi_start(menu_infos_t* mis);
-void avahi_destroy();
+void avahi_destroy(void);
 
 #endif /* PASYSTRAY_AVAHI_H */
diff -Naur pasystray-0.8.2.orig/src/menu_info.c pasystray-0.8.2/src/menu_info.c
--- pasystray-0.8.2.orig/src/menu_info.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/menu_info.c	2026-01-09 15:21:31.993662901 +0200
@@ -28,7 +28,7 @@
 #include "ui.h"
 #include "x11-property.h"
 
-menu_infos_t* menu_infos_create()
+menu_infos_t* menu_infos_create(void)
 {
     menu_infos_t* mis = g_new(menu_infos_t, 1);
 
diff -Naur pasystray-0.8.2.orig/src/menu_info.h pasystray-0.8.2/src/menu_info.h
--- pasystray-0.8.2.orig/src/menu_info.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/menu_info.h	2026-01-09 15:21:56.225534526 +0200
@@ -100,7 +100,7 @@
     GtkMenuShell* context;
 };
 
-menu_infos_t* menu_infos_create();
+menu_infos_t* menu_infos_create(void);
 void menu_infos_init(menu_infos_t* mis);
 void menu_infos_clear(menu_infos_t* mis);
 void menu_infos_destroy(menu_infos_t* mis);
diff -Naur pasystray-0.8.2.orig/src/notify.c pasystray-0.8.2/src/notify.c
--- pasystray-0.8.2.orig/src/notify.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/notify.c	2026-01-09 15:22:54.701225949 +0200
@@ -25,7 +25,7 @@
 
 #include "notify.h"
 
-void notify_initialize(){}
+void notify_initialize(void){}
 notify_handle_t notify(const char* msg, const char* body, const char* icon, gint value){ return 0; }
 void notify_update(notify_handle_t h, const char* msg, const char* body, const char* icon, gint value){}
 
@@ -34,7 +34,7 @@
 #include <libnotify/notify.h>
 typedef struct NotifyNotification* notify_handle_t;
 
-void notify_initialize()
+void notify_initialize(void)
 {
     notify_init(PACKAGE_NAME);
 }
diff -Naur pasystray-0.8.2.orig/src/notify.h pasystray-0.8.2/src/notify.h
--- pasystray-0.8.2.orig/src/notify.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/notify.h	2026-01-09 15:23:13.822125416 +0200
@@ -28,7 +28,7 @@
 
 typedef void* notify_handle_t;
 
-void notify_initialize();
+void notify_initialize(void);
 notify_handle_t notify(const char* msg, const char* body, const char* icon, gint value);
 void notify_update(notify_handle_t h, const char* msg, const char* body, const char* icon, gint value);
 
diff -Naur pasystray-0.8.2.orig/src/options.c pasystray-0.8.2/src/options.c
--- pasystray-0.8.2.orig/src/options.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/options.c	2026-01-09 15:23:37.337002039 +0200
@@ -61,7 +61,7 @@
     { .long_name = NULL }
 };
 
-GOptionEntry* get_options()
+GOptionEntry* get_options(void)
 {
     return entries;
 }
diff -Naur pasystray-0.8.2.orig/src/options.h pasystray-0.8.2/src/options.h
--- pasystray-0.8.2.orig/src/options.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/options.h	2026-01-09 15:23:45.316960230 +0200
@@ -24,7 +24,7 @@
 
 #include "menu_info.h"
 
-GOptionEntry* get_options();
+GOptionEntry* get_options(void);
 void parse_options(settings_t* settings);
 
 #endif /* PASYSTRAY_OPTIONS_H */
diff -Naur pasystray-0.8.2.orig/src/pasystray.c pasystray-0.8.2/src/pasystray.c
--- pasystray-0.8.2.orig/src/pasystray.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/pasystray.c	2026-01-09 15:25:13.732499015 +0200
@@ -81,7 +81,7 @@
 #endif
 }
 
-void quit()
+void quit(void)
 {
     g_main_loop_quit(loop);
 }
diff -Naur pasystray-0.8.2.orig/src/pasystray.h pasystray-0.8.2/src/pasystray.h
--- pasystray-0.8.2.orig/src/pasystray.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/pasystray.h	2026-01-09 15:26:41.212046271 +0200
@@ -22,8 +22,10 @@
 #ifndef PASYSTRAY_PASYSTRAY_H
 #define PASYSTRAY_PASYSTRAY_H
 
-void init();
-void quit();
-void destroy();
+#include "menu_info.h"
+
+void init(settings_t* settings);
+void quit(void);
+void destroy(settings_t* settings);
 
 #endif /* PASYSTRAY_PASYSTRAY_H */
diff -Naur pasystray-0.8.2.orig/src/pulseaudio.c pasystray-0.8.2/src/pulseaudio.c
--- pasystray-0.8.2.orig/src/pulseaudio.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/pulseaudio.c	2026-01-09 15:27:32.308784636 +0200
@@ -40,7 +40,7 @@
     pulseaudio_connect(mis);
 }
 
-void pulseaudio_destroy()
+void pulseaudio_destroy(void)
 {
     pulseaudio_quit(NULL);
 }
diff -Naur pasystray-0.8.2.orig/src/pulseaudio.h pasystray-0.8.2/src/pulseaudio.h
--- pasystray-0.8.2.orig/src/pulseaudio.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/pulseaudio.h	2026-01-09 15:28:05.771631159 +0200
@@ -27,11 +27,10 @@
 #include "menu_info.h"
 
 void pulseaudio_init(menu_infos_t* mis);
-void pulseaudio_destroy();
+void pulseaudio_destroy(void);
 void pulseaudio_prepare_context(menu_infos_t* mis);
 void pulseaudio_connect(menu_infos_t* mis);
 void pulseaudio_reconnect(menu_infos_t* mis);
-void pulseaudio_start();
 
 void pulseaudio_context_state_cb(pa_context* c, void* userdata);
 
diff -Naur pasystray-0.8.2.orig/src/systray.c pasystray-0.8.2/src/systray.c
--- pasystray-0.8.2.orig/src/systray.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/systray.c	2026-01-09 15:28:45.295450117 +0200
@@ -328,7 +328,7 @@
         menu_info_item_remove(mii->submenu, item->index);
 }
 
-void systray_about_dialog()
+void systray_about_dialog(void)
 {
     char *authors[] = { _("Christoph Gysin <christoph.gysin@gmail.com>"),
                         NULL };
diff -Naur pasystray-0.8.2.orig/src/systray.h pasystray-0.8.2/src/systray.h
--- pasystray-0.8.2.orig/src/systray.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/systray.h	2026-01-09 15:28:54.559407720 +0200
@@ -57,7 +57,7 @@
 void systray_update_item_in_all_submenus(menu_info_item_t* item, menu_info_t* submenu);
 void systray_remove_item_from_all_submenus(menu_info_item_t* item, menu_info_t* submenu);
 
-void systray_about_dialog();
+void systray_about_dialog(void);
 
 void systray_click_cb(GtkStatusIcon* icon, GdkEventButton* ev, gpointer userdata);
 void systray_scroll_cb(guint state, GdkScrollDirection direction, menu_infos_t* mis);
diff -Naur pasystray-0.8.2.orig/src/ui.c pasystray-0.8.2/src/ui.c
--- pasystray-0.8.2.orig/src/ui.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/ui.c	2026-01-09 15:29:41.291194042 +0200
@@ -123,17 +123,17 @@
     systray_impl_set_icon(mis->systray, mii->icon);
 }
 
-GtkDialog* ui_renamedialog()
+GtkDialog* ui_renamedialog(void)
 {
     return (GtkDialog*) gtk_builder_get_object(builder, "renamedialog");
 }
 
-GtkLabel* ui_renamedialog_label()
+GtkLabel* ui_renamedialog_label(void)
 {
     return (GtkLabel*) gtk_builder_get_object(builder, "label");
 }
 
-GtkEntry* ui_renamedialog_entry()
+GtkEntry* ui_renamedialog_entry(void)
 {
     return (GtkEntry*) gtk_builder_get_object(builder, "entry");
 }
diff -Naur pasystray-0.8.2.orig/src/ui.h pasystray-0.8.2/src/ui.h
--- pasystray-0.8.2.orig/src/ui.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/ui.h	2026-01-09 15:31:02.946830546 +0200
@@ -28,9 +28,9 @@
 void ui_load(settings_t* settings);
 void ui_set_volume_icon(menu_info_item_t* mii);
 void ui_update_systray_icon(menu_info_item_t* mii);
-GtkDialog* ui_renamedialog();
-GtkLabel* ui_renamedialog_label();
-GtkEntry* ui_renamedialog_entry();
+GtkDialog* ui_renamedialog(void);
+GtkLabel* ui_renamedialog_label(void);
+GtkEntry* ui_renamedialog_entry(void);
 GtkDialog* ui_errordialog(const gchar* title, const gchar* message);
 
 #endif /* PASYSTRAY_UI_H */
diff -Naur pasystray-0.8.2.orig/src/x11-property.c pasystray-0.8.2/src/x11-property.c
--- pasystray-0.8.2.orig/src/x11-property.c	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/x11-property.c	2026-01-09 15:32:02.318573763 +0200
@@ -25,7 +25,7 @@
 
 #include <stdlib.h>
 
-void x11_property_init(){}
+void x11_property_init(void){}
 void x11_property_set(const char* key, const char* value){}
 void x11_property_del(const char* key){}
 char* x11_property_get(const char* key){ return NULL; }
@@ -40,7 +40,7 @@
 static Display* display = NULL;
 static Window window;
 
-void x11_property_init()
+void x11_property_init(void)
 {
     display = gdk_x11_get_default_xdisplay();
     window = RootWindow(display, 0);
diff -Naur pasystray-0.8.2.orig/src/x11-property.h pasystray-0.8.2/src/x11-property.h
--- pasystray-0.8.2.orig/src/x11-property.h	2023-02-10 23:11:00.000000000 +0200
+++ pasystray-0.8.2/src/x11-property.h	2026-01-09 15:32:17.326508862 +0200
@@ -22,7 +22,7 @@
 #ifndef PASYSTRAY_X11_PROPERTY_H
 #define PASYSTRAY_X11_PROPERTY_H
 
-void x11_property_init();
+void x11_property_init(void);
 void x11_property_set(const char* key, const char* value);
 void x11_property_del(const char* key);
 char* x11_property_get(const char* key);