diff --git a/plugins/checksum/checksum.c b/plugins/checksum/checksum.c
index 9a7f0ebd..6aa64b64 100644
--- a/plugins/checksum/checksum.c
+++ b/plugins/checksum/checksum.c
@@ -58,7 +58,7 @@ set_limit (char *size)
 }
 
 static int
-get_limit ()
+get_limit (void)
 {
 	int size = hexchat_pluginpref_get_int (ph, "limit");
 
diff --git a/plugins/fishlim/keystore.c b/plugins/fishlim/keystore.c
index 84373996..298b9fa3 100644
--- a/plugins/fishlim/keystore.c
+++ b/plugins/fishlim/keystore.c
@@ -39,7 +39,7 @@ static char *keystore_password = NULL;
 /**
  * Opens the key store file: ~/.config/hexchat/addon_fishlim.conf
  */
-static GKeyFile *getConfigFile() {
+static GKeyFile *getConfigFile(void) {
     gchar *filename = get_config_filename();
     
     GKeyFile *keyfile = g_key_file_new();
@@ -55,7 +55,7 @@ static GKeyFile *getConfigFile() {
 /**
  * Returns the key store password, or the default.
  */
-static const char *get_keystore_password() {
+static const char *get_keystore_password(void) {
     return (keystore_password != NULL ?
         keystore_password :
         /* Silly default value... */
diff --git a/plugins/fishlim/plugin_hexchat.c b/plugins/fishlim/plugin_hexchat.c
index 556a2f51..0afecd82 100644
--- a/plugins/fishlim/plugin_hexchat.c
+++ b/plugins/fishlim/plugin_hexchat.c
@@ -48,7 +48,7 @@ static hexchat_plugin *ph;
 /**
  * Returns the path to the key store file.
  */
-gchar *get_config_filename() {
+gchar *get_config_filename(void) {
     char *filename_fs, *filename_utf8;
 
     filename_utf8 = g_build_filename(hexchat_get_info(ph, "configdir"), "addon_fishlim.conf", NULL);
diff --git a/plugins/fishlim/plugin_hexchat.h b/plugins/fishlim/plugin_hexchat.h
index f60522e6..d619d239 100644
--- a/plugins/fishlim/plugin_hexchat.h
+++ b/plugins/fishlim/plugin_hexchat.h
@@ -25,7 +25,7 @@
 #ifndef PLUGIN_HEXCHAT_H
 #define PLUGIN_HEXCHAT_H
 
-gchar *get_config_filename();
+gchar *get_config_filename(void);
 int irc_nick_cmp (const char *, const char *);
 
 #endif
diff --git a/plugins/python/python.c b/plugins/python/python.c
index 1f9c7cc9..b97761f5 100644
--- a/plugins/python/python.c
+++ b/plugins/python/python.c
@@ -273,7 +273,7 @@ typedef struct {
 
 static PyObject *Util_BuildList(char *word[]);
 static PyObject *Util_BuildEOLList(char *word[]);
-static void Util_Autoload();
+static void Util_Autoload(void);
 static char *Util_Expand(char *filename);
 
 static int Callback_Server(char *word[], char *word_eol[], hexchat_event_attrs *attrs, void *userdata);
@@ -283,7 +283,7 @@ static int Callback_Print(char *word[], void *userdata);
 static int Callback_Timer(void *userdata);
 static int Callback_ThreadTimer(void *userdata);
 
-static PyObject *XChatOut_New();
+static PyObject *XChatOut_New(void);
 static PyObject *XChatOut_write(PyObject *self, PyObject *args);
 static void XChatOut_dealloc(PyObject *self);
 
@@ -300,7 +300,7 @@ static PyObject *Context_FromContext(hexchat_context *context);
 static PyObject *Context_FromServerAndChannel(char *server, char *channel);
 
 static PyObject *Plugin_New(char *filename, PyObject *xcoobj);
-static PyObject *Plugin_GetCurrent();
+static PyObject *Plugin_GetCurrent(void);
 static PluginObject *Plugin_ByString(char *str);
 static Hook *Plugin_AddHook(int type, PyObject *plugin, PyObject *callback,
 			    PyObject *userdata, char *name, void *data);
@@ -336,11 +336,11 @@ static PyObject *Module_hexchat_pluginpref_list(PyObject *self, PyObject *args);
 static void IInterp_Exec(char *command);
 static int IInterp_Cmd(char *word[], char *word_eol[], void *userdata);
 
-static void Command_PyList();
+static void Command_PyList(void);
 static void Command_PyLoad(char *filename);
 static void Command_PyUnload(char *name);
 static void Command_PyReload(char *name);
-static void Command_PyAbout();
+static void Command_PyAbout(void);
 static int Command_Py(char *word[], char *word_eol[], void *userdata);
 
 /* ===================================================================== */
@@ -2518,7 +2518,7 @@ IInterp_Cmd(char *word[], char *word_eol[], void *userdata)
 /* Python command handling */
 
 static void
-Command_PyList()
+Command_PyList(void)
 {
 	GSList *list;
 	list = plugin_list;
@@ -2585,7 +2585,7 @@ Command_PyReload(char *name)
 }
 
 static void
-Command_PyAbout()
+Command_PyAbout(void)
 {
 	hexchat_print(ph, about);
 }
@@ -2777,7 +2777,7 @@ hexchat_plugin_init(hexchat_plugin *plugin_handle,
 }
 
 int
-hexchat_plugin_deinit()
+hexchat_plugin_deinit(void)
 {
 	GSList *list;
 
diff --git a/src/common/dcc.c b/src/common/dcc.c
index a7ed0988..6c5b117e 100644
--- a/src/common/dcc.c
+++ b/src/common/dcc.c
@@ -83,7 +83,7 @@ static gboolean dcc_send_data (GIOChannel *, GIOCondition, struct DCC *);
 static gboolean dcc_read (GIOChannel *, GIOCondition, struct DCC *);
 static gboolean dcc_read_ack (GIOChannel *source, GIOCondition condition, struct DCC *dcc);
 
-static int new_id()
+static int new_id(void)
 {
 	static int id = 0;
 	if (id == 0)
diff --git a/src/common/fe.h b/src/common/fe.h
index a3bd2afa..209abb00 100644
--- a/src/common/fe.h
+++ b/src/common/fe.h
@@ -179,6 +179,6 @@ typedef enum
 void fe_tray_set_icon (feicon icon);
 void fe_tray_set_tooltip (const char *text);
 void fe_open_chan_list (server *serv, char *filter, int do_refresh);
-const char *fe_get_default_font ();
+const char *fe_get_default_font (void);
 
 #endif
diff --git a/src/common/plugin-identd.h b/src/common/plugin-identd.h
index 5efc2600..6aee9f6d 100644
--- a/src/common/plugin-identd.h
+++ b/src/common/plugin-identd.h
@@ -23,6 +23,6 @@
 int identd_plugin_init (hexchat_plugin *plugin_handle, char **plugin_name,
 				char **plugin_desc, char **plugin_version, char *arg);
 
-int identd_plugin_deinit ();
+int identd_plugin_deinit (void);
 
 #endif
diff --git a/src/common/plugin.c b/src/common/plugin.c
index a397c878..6d362ffb 100644
--- a/src/common/plugin.c
+++ b/src/common/plugin.c
@@ -427,7 +427,7 @@ plugin_auto_load_cb (char *filename)
 }
 
 static char *
-plugin_get_libdir ()
+plugin_get_libdir (void)
 {
 	const char *libdir;
 
diff --git a/src/common/text.c b/src/common/text.c
index c2db9254..2f20d171 100644
--- a/src/common/text.c
+++ b/src/common/text.c
@@ -1478,7 +1478,7 @@ static char * const pevt_discon_help[] = {
 #include "textevents.h"
 
 static void
-pevent_load_defaults ()
+pevent_load_defaults (void)
 {
 	int i;
 
@@ -1495,7 +1495,7 @@ pevent_load_defaults ()
 }
 
 void
-pevent_make_pntevts ()
+pevent_make_pntevts (void)
 {
 	int i, m;
 	char out[1024];
@@ -1637,7 +1637,7 @@ pevent_load (char *filename)
 }
 
 static void
-pevent_check_all_loaded ()
+pevent_check_all_loaded (void)
 {
 	int i;
 
diff --git a/src/common/text.h b/src/common/text.h
index 28fc0c0d..485b7ce8 100644
--- a/src/common/text.h
+++ b/src/common/text.h
@@ -69,7 +69,7 @@ extern const gchar* arbitrary_encoding_fallback_string;
 void sound_play (const char *file, gboolean quiet);
 void sound_play_event (int i);
 void sound_beep (session *);
-void sound_load ();
-void sound_save ();
+void sound_load (void);
+void sound_save (void);
 
 #endif
diff --git a/src/fe-gtk/fkeys.c b/src/fe-gtk/fkeys.c
index af0e149a..fe8f3e6c 100644
--- a/src/fe-gtk/fkeys.c
+++ b/src/fe-gtk/fkeys.c
@@ -94,8 +94,8 @@ struct gcomp_data
 	int elen;
 };
 
-static int key_load_kbs ();
-static int key_save_kbs ();
+static int key_load_kbs (void);
+static int key_save_kbs (void);
 static int key_action_handle_command (GtkWidget * wid, GdkEventKey * evt,
 												  char *d1, char *d2,
 												  struct session *sess);
diff --git a/src/fe-gtk/ignoregui.c b/src/fe-gtk/ignoregui.c
index a30b8cd1..08d837ec 100644
--- a/src/fe-gtk/ignoregui.c
+++ b/src/fe-gtk/ignoregui.c
@@ -306,7 +306,7 @@ ignore_new_entry_clicked (GtkWidget * wid, struct session *sess)
 }
 
 static void
-close_ignore_gui_callback ()
+close_ignore_gui_callback (void)
 {
 	ignore_save ();
 	ignorewin = 0;
diff --git a/src/fe-gtk/menu.c b/src/fe-gtk/menu.c
index 902af92e..046e6afe 100644
--- a/src/fe-gtk/menu.c
+++ b/src/fe-gtk/menu.c
@@ -375,7 +375,7 @@ menu_quick_sub (char *name, GtkWidget *menu, GtkWidget **sub_item_ret, int flags
 }
 
 static GtkWidget *
-menu_quick_endsub ()
+menu_quick_endsub (void)
 {
 	/* Just delete the first element in the linked list pointed to by first */
 	if (submenu_list)
@@ -1259,7 +1259,7 @@ menu_quit (GtkWidget * wid, gpointer none)
 }
 
 static void
-menu_search ()
+menu_search (void)
 {
 	mg_search_toggle (current_sess);
 }
diff --git a/src/fe-gtk/plugin-tray.c b/src/fe-gtk/plugin-tray.c
index 077a7c63..ef70b032 100644
--- a/src/fe-gtk/plugin-tray.c
+++ b/src/fe-gtk/plugin-tray.c
@@ -80,7 +80,7 @@ static int tray_restore_timer = 0;
 
 
 void tray_apply_setup (void);
-static gboolean tray_menu_try_restore ();
+static gboolean tray_menu_try_restore (void);
 static void tray_cleanup (void);
 static void tray_init (void);
 
@@ -391,7 +391,7 @@ tray_menu_notify_cb (GObject *tray, GParamSpec *pspec, gpointer user_data)
 }
 
 static gboolean
-tray_menu_try_restore ()
+tray_menu_try_restore (void)
 {
 	tray_cleanup();
 	tray_init();
diff --git a/src/fe-gtk/sexy-spell-entry.c b/src/fe-gtk/sexy-spell-entry.c
index f57c7f41..45bc132c 100644
--- a/src/fe-gtk/sexy-spell-entry.c
+++ b/src/fe-gtk/sexy-spell-entry.c
@@ -155,7 +155,7 @@ spell_accumulator(GSignalInvocationHint *hint, GValue *return_accu, const GValue
 }
 
 static void
-initialize_enchant ()
+initialize_enchant (void)
 {
 	GModule *enchant;
 	gpointer funcptr;