diff --git a/core/android.cpp b/core/android.cpp
index fef58a48c..3a305dff6 100644
--- a/core/android.cpp
+++ b/core/android.cpp
@@ -46,7 +46,7 @@ const char *system_divelist_default_font = android_system_divelist_default_font;
 double system_divelist_default_font_size = -1;
 
 int get_usb_fd(uint16_t idVendor, uint16_t idProduct);
-void subsurface_OS_pref_setup(void)
+void subsurface_OS_pref_setup()
 {
 }
 
@@ -56,13 +56,13 @@ bool subsurface_ignore_font(const char *font)
 	return false;
 }
 
-const char *system_default_directory(void)
+const char *system_default_directory()
 {
 	static const std::string path = system_default_path();
 	return path.c_str();
 }
 
-const char *system_default_filename(void)
+const char *system_default_filename()
 {
 	static const std::string fn = make_default_filename();
 	return fn.c_str();
@@ -235,12 +235,12 @@ int subsurface_zip_close(struct zip *zip)
 }
 
 /* win32 console */
-void subsurface_console_init(void)
+void subsurface_console_init()
 {
 	/* NOP */
 }
 
-void subsurface_console_exit(void)
+void subsurface_console_exit()
 {
 	/* NOP */
 }
diff --git a/core/dive.cpp b/core/dive.cpp
index 80a441dfb..343e90bd4 100644
--- a/core/dive.cpp
+++ b/core/dive.cpp
@@ -163,7 +163,7 @@ int dive_getUniqID()
 	return maxId;
 }
 
-struct dive *alloc_dive(void)
+struct dive *alloc_dive()
 {
 	struct dive *dive;
 
diff --git a/core/dive.h b/core/dive.h
index 1c8696110..492e67fcf 100644
--- a/core/dive.h
+++ b/core/dive.h
@@ -158,11 +158,11 @@ extern int save_dive_sites_logic(const char *filename, const struct dive_site *s
 struct membuffer;
 extern void save_one_dive_to_mb(struct membuffer *b, struct dive *dive, bool anonymize);
 
-extern void subsurface_console_init(void);
-extern void subsurface_console_exit(void);
-extern bool subsurface_user_is_root(void);
+extern void subsurface_console_init();
+extern void subsurface_console_exit();
+extern bool subsurface_user_is_root();
 
-extern struct dive *alloc_dive(void);
+extern struct dive *alloc_dive();
 extern void free_dive(struct dive *);
 extern void record_dive_to_table(struct dive *dive, struct dive_table *table);
 extern void clear_dive(struct dive *dive);
diff --git a/core/eventtype.h b/core/eventtype.h
index 8f0ecd28e..94fad72db 100644
--- a/core/eventtype.h
+++ b/core/eventtype.h
@@ -6,7 +6,7 @@
 #include <vector>
 #include <QString>
 
-extern void clear_event_types(void);
+extern void clear_event_types();
 extern void remember_event_type(const struct event *ev);
 extern bool is_event_type_hidden(const struct event *ev);
 extern void hide_event_type(const struct event *ev);
diff --git a/core/filterpreset.cpp b/core/filterpreset.cpp
index 518b2b264..2366e88e2 100644
--- a/core/filterpreset.cpp
+++ b/core/filterpreset.cpp
@@ -9,7 +9,7 @@ static filter_preset_table &global_table()
 	return *divelog.filter_presets;
 }
 
-int filter_presets_count(void)
+int filter_presets_count()
 {
 	return (int)global_table().size();
 }
diff --git a/core/filterpreset.h b/core/filterpreset.h
index 807a1c48c..5485f5bde 100644
--- a/core/filterpreset.h
+++ b/core/filterpreset.h
@@ -30,7 +30,7 @@ struct filter_preset_table : public std::vector<filter_preset>
 };
 
 // The C IO code accesses the filter presets via integer indices.
-extern int filter_presets_count(void);
+extern int filter_presets_count();
 extern const char *filter_preset_fulltext_mode(int preset); // string mode of fulltext query. ownership is *not* passed to caller.
 extern int filter_preset_constraint_count(int preset); // number of constraints in the filter preset.
 extern const struct filter_constraint *filter_preset_constraint(int preset, int constraint); // get constraint. ownership is *not* passed to caller.
diff --git a/core/git-access.h b/core/git-access.h
index ed9e4ed5e..e596e8b82 100644
--- a/core/git-access.h
+++ b/core/git-access.h
@@ -22,7 +22,7 @@ enum remote_transport { RT_LOCAL, RT_HTTPS, RT_SSH, RT_OTHER };
 
 extern bool git_local_only;
 extern bool git_remote_sync_successful;
-extern void clear_git_id(void);
+extern void clear_git_id();
 extern void set_git_id(const struct git_oid *);
 void set_git_update_cb(int(*)(const char *));
 int git_storage_update_progress(const char *text);
diff --git a/core/ios.cpp b/core/ios.cpp
index 15f1c4501..ecb81777f 100644
--- a/core/ios.cpp
+++ b/core/ios.cpp
@@ -36,7 +36,7 @@ const char mac_system_divelist_default_font[] = "Arial";
 const char *system_divelist_default_font = mac_system_divelist_default_font;
 double system_divelist_default_font_size = -1.0;
 
-void subsurface_OS_pref_setup(void)
+void subsurface_OS_pref_setup()
 {
 	// nothing
 }
@@ -47,13 +47,13 @@ bool subsurface_ignore_font(const char*)
 	return false;
 }
 
-const char *system_default_directory(void)
+const char *system_default_directory()
 {
 	static const std::string path = system_default_path();
 	return path.c_str();
 }
 
-const char *system_default_filename(void)
+const char *system_default_filename()
 {
 	static const std::string fn = make_default_filename();
 	return fn.c_str();
@@ -107,12 +107,12 @@ int subsurface_zip_close(struct zip *zip)
 }
 
 /* win32 console */
-void subsurface_console_init(void)
+void subsurface_console_init()
 {
 	/* NOP */
 }
 
-void subsurface_console_exit(void)
+void subsurface_console_exit()
 {
 	/* NOP */
 }
diff --git a/core/load-git.cpp b/core/load-git.cpp
index 3157a28b8..cb488e2d5 100644
--- a/core/load-git.cpp
+++ b/core/load-git.cpp
@@ -1846,7 +1846,7 @@ static int load_dives_from_tree(git_repository *repo, git_tree *tree, struct git
 	return 0;
 }
 
-void clear_git_id(void)
+void clear_git_id()
 {
 	saved_git_id.clear();
 }
diff --git a/core/macos.cpp b/core/macos.cpp
index 4c7c1426e..50f32448e 100644
--- a/core/macos.cpp
+++ b/core/macos.cpp
@@ -52,7 +52,7 @@ const char mac_system_divelist_default_font[] = "Arial";
 const char *system_divelist_default_font = mac_system_divelist_default_font;
 double system_divelist_default_font_size = -1.0;
 
-void subsurface_OS_pref_setup(void)
+void subsurface_OS_pref_setup()
 {
 	// nothing
 }
@@ -63,13 +63,13 @@ bool subsurface_ignore_font(const char *)
 	return false;
 }
 
-const char *system_default_directory(void)
+const char *system_default_directory()
 {
 	static const std::string path = system_default_path();
 	return path.c_str();
 }
 
-const char *system_default_filename(void)
+const char *system_default_filename()
 {
 	static const std::string fn = make_default_filename();
 	return fn.c_str();
@@ -183,12 +183,12 @@ int subsurface_zip_close(struct zip *zip)
 }
 
 /* win32 console */
-void subsurface_console_init(void)
+void subsurface_console_init()
 {
 	/* NOP */
 }
 
-void subsurface_console_exit(void)
+void subsurface_console_exit()
 {
 	/* NOP */
 }
diff --git a/core/membuffer.cpp b/core/membuffer.cpp
index 2b8b7c8bc..86872e6af 100644
--- a/core/membuffer.cpp
+++ b/core/membuffer.cpp
@@ -63,7 +63,7 @@ void strip_mb(struct membuffer *b)
  * interface very complex, we'll just die. It won't happen
  * unless you're running on a potato.
  */
-static void oom(void)
+static void oom()
 {
 	fprintf(stderr, "Out of memory\n");
 	exit(1);
diff --git a/core/parse-xml.cpp b/core/parse-xml.cpp
index b623e9ddd..17c89168c 100644
--- a/core/parse-xml.cpp
+++ b/core/parse-xml.cpp
@@ -2274,12 +2274,12 @@ int parse_dlf_buffer(unsigned char *buffer, size_t size, struct divelog *log)
 }
 
 
-void parse_xml_init(void)
+void parse_xml_init()
 {
 	LIBXML_TEST_VERSION
 }
 
-void parse_xml_exit(void)
+void parse_xml_exit()
 {
 	xmlCleanupParser();
 }
diff --git a/core/parse.h b/core/parse.h
index f9152c8b0..ac905214e 100644
--- a/core/parse.h
+++ b/core/parse.h
@@ -148,9 +148,9 @@ void nonmatch(const char *type, const char *name, char *buffer);
 int atoi_n(char *ptr, unsigned int len);
 void utf8_string(const char *buffer, char **res);
 
-void parse_xml_init(void);
+void parse_xml_init();
 int parse_xml_buffer(const char *url, const char *buf, int size, struct divelog *log, const struct xml_params *params);
-void parse_xml_exit(void);
+void parse_xml_exit();
 int parse_dm4_buffer(sqlite3 *handle, const char *url, const char *buf, int size, struct divelog *log);
 int parse_dm5_buffer(sqlite3 *handle, const char *url, const char *buf, int size, struct divelog *log);
 int parse_seac_buffer(sqlite3 *handle, const char *url, const char *buf, int size, struct divelog *log);
diff --git a/core/pref.cpp b/core/pref.cpp
index 2a04ba7ff..4bce25ed8 100644
--- a/core/pref.cpp
+++ b/core/pref.cpp
@@ -149,7 +149,7 @@ void copy_prefs(struct preferences *src, struct preferences *dest)
  * These are not real leaks but they plug the holes found by eg.
  * valgrind so you can find the real leaks.
  */
-void free_prefs(void)
+void free_prefs()
 {
 	// nop
 }
diff --git a/core/pref.h b/core/pref.h
index 214fcd551..85d78afcf 100644
--- a/core/pref.h
+++ b/core/pref.h
@@ -214,7 +214,7 @@ extern struct preferences prefs, default_prefs, git_prefs;
 extern const char *system_divelist_default_font;
 extern double system_divelist_default_font_size;
 
-extern const char *system_default_directory(void);
+extern const char *system_default_directory();
 extern const char *system_default_filename();
 extern bool subsurface_ignore_font(const char *font);
 extern void subsurface_OS_pref_setup();
diff --git a/core/qt-ble.cpp b/core/qt-ble.cpp
index 2df255576..fdbef3bce 100644
--- a/core/qt-ble.cpp
+++ b/core/qt-ble.cpp
@@ -414,7 +414,7 @@ dc_status_t BLEObject::read(void *data, size_t size, size_t *actual)
 //
 // That's wrong, but works for the simple case.
 //
-dc_status_t BLEObject::select_preferred_service(void)
+dc_status_t BLEObject::select_preferred_service()
 {
 	// Wait for each service to finish discovering
 	for (const QLowEnergyService *s: services) {
diff --git a/core/qt-ble.h b/core/qt-ble.h
index d99dbadb5..f4750a9ae 100644
--- a/core/qt-ble.h
+++ b/core/qt-ble.h
@@ -32,7 +32,7 @@ public:
 
 	inline QLowEnergyService *preferredService() { return preferred; }
 	inline int descriptorWritten() { return desc_written; }
-	dc_status_t select_preferred_service(void);
+	dc_status_t select_preferred_service();
 
 public slots:
 	void addService(const QBluetoothUuid &newService);
diff --git a/core/selection.cpp b/core/selection.cpp
index 52178cb2e..91d2e58b0 100644
--- a/core/selection.cpp
+++ b/core/selection.cpp
@@ -63,7 +63,7 @@ bool consecutive_selected()
 }
 
 #if DEBUG_SELECTION_TRACKING
-void dump_selection(void)
+void dump_selection()
 {
 	int i;
 	struct dive *dive;
diff --git a/core/selection.h b/core/selection.h
index d21ff0a98..a1e92e8a4 100644
--- a/core/selection.h
+++ b/core/selection.h
@@ -12,18 +12,18 @@ struct dive;
 extern int amount_selected;
 extern struct dive *current_dive;
 
-extern struct dive *first_selected_dive(void);
-extern struct dive *last_selected_dive(void);
-extern bool consecutive_selected(void);
+extern struct dive *first_selected_dive();
+extern struct dive *last_selected_dive();
+extern bool consecutive_selected();
 extern void select_newest_visible_dive();
 extern void select_single_dive(struct dive *d); // wrapper for setSelection() with a single dive. NULL clears the selection.
 extern void select_trip(struct dive_trip *trip);
 extern void deselect_trip(struct dive_trip *trip);
 extern struct dive_trip *single_selected_trip(); // returns trip if exactly one trip is selected, NULL otherwise.
-extern void clear_selection(void);
+extern void clear_selection();
 
 #if DEBUG_SELECTION_TRACKING
-extern void dump_selection(void);
+extern void dump_selection();
 #endif
 
 // Reset the selection to the dives of the "selection" vector and send the appropriate signals.
diff --git a/core/serial_ftdi.cpp b/core/serial_ftdi.cpp
index daaecadfb..0be317f7f 100644
--- a/core/serial_ftdi.cpp
+++ b/core/serial_ftdi.cpp
@@ -106,7 +106,7 @@ static dc_status_t serial_ftdi_get_transmitted (ftdi_serial_t *device)
 /*
  * Get an msec value on some random base
  */
-static unsigned int serial_ftdi_get_msec(void)
+static unsigned int serial_ftdi_get_msec()
 {
 #ifdef _WIN32
 	return GetTickCount();
diff --git a/core/subsurfacestartup.cpp b/core/subsurfacestartup.cpp
index 86d600109..9cfd9f7f9 100644
--- a/core/subsurfacestartup.cpp
+++ b/core/subsurfacestartup.cpp
@@ -191,7 +191,7 @@ void parse_argument(const char *arg)
  * I guess Burma and Liberia should trigger this too. I'm too
  * lazy to look up the territory names, though.
  */
-void setup_system_prefs(void)
+void setup_system_prefs()
 {
 	const char *env;
 
diff --git a/core/subsurfacestartup.h b/core/subsurfacestartup.h
index ddb18b53f..1180ad2a5 100644
--- a/core/subsurfacestartup.h
+++ b/core/subsurfacestartup.h
@@ -5,11 +5,11 @@
 extern bool imported;
 extern int quit, force_root, ignore_bt;
 
-void setup_system_prefs(void);
+void setup_system_prefs();
 void parse_argument(const char *arg);
-void free_prefs(void);
-void print_files(void);
-void print_version(void);
+void free_prefs();
+void print_files();
+void print_version();
 
 extern char *settings_suffix;
 
diff --git a/core/trip.cpp b/core/trip.cpp
index b83928502..df66f211a 100644
--- a/core/trip.cpp
+++ b/core/trip.cpp
@@ -10,7 +10,7 @@
 #include "core/errorhelper.h"
 
 #ifdef DEBUG_TRIP
-void dump_trip_list(void)
+void dump_trip_list()
 {
 	dive_trip_t *trip;
 	int i = 0;
@@ -126,7 +126,7 @@ void remove_dive_from_trip(struct dive *dive, struct trip_table *trip_table_arg)
 		delete_trip(trip, trip_table_arg);
 }
 
-dive_trip_t *alloc_trip(void)
+dive_trip_t *alloc_trip()
 {
 	dive_trip_t *res = (dive_trip_t *)calloc(1, sizeof(dive_trip_t));
 	res->id = dive_getUniqID();
diff --git a/core/trip.h b/core/trip.h
index cb4a8da0f..df15ee770 100644
--- a/core/trip.h
+++ b/core/trip.h
@@ -37,7 +37,7 @@ extern bool trip_less_than(const struct dive_trip *a, const struct dive_trip *b)
 extern int comp_trips(const struct dive_trip *a, const struct dive_trip *b);
 extern void sort_trip_table(struct trip_table *table);
 
-extern dive_trip_t *alloc_trip(void);
+extern dive_trip_t *alloc_trip();
 extern dive_trip_t *create_trip_from_dive(struct dive *dive);
 extern dive_trip_t *get_dives_to_autogroup(struct dive_table *table, int start, int *from, int *to, bool *allocated);
 extern dive_trip_t *get_trip_for_new_dive(struct dive *new_dive, bool *allocated);
@@ -53,7 +53,7 @@ void move_trip_table(struct trip_table *src, struct trip_table *dst);
 void clear_trip_table(struct trip_table *table);
 
 #ifdef DEBUG_TRIP
-extern void dump_trip_list(void);
+extern void dump_trip_list();
 #endif
 
 /* Make pointers to dive_trip and trip_table "Qt metatypes" so that they can be
diff --git a/core/units.h b/core/units.h
index c1c68cc59..5465e07eb 100644
--- a/core/units.h
+++ b/core/units.h
@@ -325,7 +325,7 @@ struct units {
 
 extern const struct units SI_units, IMPERIAL_units;
 
-extern const struct units *get_units(void);
+extern const struct units *get_units();
 
 extern int get_pressure_units(int mb, const char **units);
 extern double get_depth_units(int mm, int *frac, const char **units);
diff --git a/core/unix.cpp b/core/unix.cpp
index dcae486a3..9692fd136 100644
--- a/core/unix.cpp
+++ b/core/unix.cpp
@@ -40,7 +40,7 @@ const char unix_system_divelist_default_font[] = "Sans";
 const char *system_divelist_default_font = unix_system_divelist_default_font;
 double system_divelist_default_font_size = -1.0;
 
-void subsurface_OS_pref_setup(void)
+void subsurface_OS_pref_setup()
 {
 	// nothing
 }
@@ -51,13 +51,13 @@ bool subsurface_ignore_font(const char *)
 	return false;
 }
 
-const char *system_default_directory(void)
+const char *system_default_directory()
 {
 	static const std::string path = system_default_path();
 	return path.c_str();
 }
 
-const char *system_default_filename(void)
+const char *system_default_filename()
 {
 	static const std::string fn = make_default_filename();
 	return fn.c_str();
@@ -187,12 +187,12 @@ int subsurface_zip_close(struct zip *zip)
 }
 
 /* win32 console */
-void subsurface_console_init(void)
+void subsurface_console_init()
 {
 	/* NOP */
 }
 
-void subsurface_console_exit(void)
+void subsurface_console_exit()
 {
 	/* NOP */
 }
diff --git a/core/version.cpp b/core/version.cpp
index 811e763b8..09c23d33b 100644
--- a/core/version.cpp
+++ b/core/version.cpp
@@ -2,12 +2,12 @@
 #include "ssrf-version.h"
 
 // let's leave the two redundant functions in case we change our minds on git SHAs
-const char *subsurface_git_version(void)
+const char *subsurface_git_version()
 {
 	return CANONICAL_VERSION_STRING_4;
 }
 
-const char *subsurface_canonical_version(void)
+const char *subsurface_canonical_version()
 {
 	return CANONICAL_VERSION_STRING;
 }
diff --git a/core/version.h b/core/version.h
index 148f2d559..37a7d4df3 100644
--- a/core/version.h
+++ b/core/version.h
@@ -1,7 +1,7 @@
 #ifndef VERSION_H
 #define VERSION_H
 
-const char *subsurface_git_version(void);
-const char *subsurface_canonical_version(void);
+const char *subsurface_git_version();
+const char *subsurface_canonical_version();
 
 #endif
diff --git a/core/webservice.h b/core/webservice.h
index 4831072dd..bdb9ddfbf 100644
--- a/core/webservice.h
+++ b/core/webservice.h
@@ -2,7 +2,7 @@
 #ifndef WEBSERVICE_H
 #define WEBSERVICE_H
 
-//extern void webservice_download_dialog(void);
+//extern void webservice_download_dialog();
 //extern bool webservice_request_user_xml(const gchar *, gchar **, unsigned int *, unsigned int *);
 extern int divelogde_upload(char *fn, char **error);
 extern unsigned int download_dialog_parse_response(char *xmldata, unsigned int len);
diff --git a/core/windows.cpp b/core/windows.cpp
index c244cfc5a..ae8e64b76 100644
--- a/core/windows.cpp
+++ b/core/windows.cpp
@@ -105,7 +105,7 @@ const char current_system_divelist_default_font[] = "Segoe UI";
 const char *system_divelist_default_font = non_standard_system_divelist_default_font;
 double system_divelist_default_font_size = -1;
 
-void subsurface_OS_pref_setup(void)
+void subsurface_OS_pref_setup()
 {
 	if (isWin7Or8())
 		system_divelist_default_font = current_system_divelist_default_font;
@@ -124,13 +124,13 @@ bool subsurface_ignore_font(const char *font)
 
 /* '\' not included at the end.
  */
-const char *system_default_directory(void)
+const char *system_default_directory()
 {
 	static std::string path = utf16_to_utf8(system_default_path());
 	return path.c_str();
 }
 
-const char *system_default_filename(void)
+const char *system_default_filename()
 {
 	static std::string path = utf16_to_utf8(make_default_filename());
 	return path.c_str();
@@ -373,7 +373,7 @@ static struct {
 } console_desc;
 #endif
 
-void subsurface_console_init(void)
+void subsurface_console_init()
 {
 	/* if this is a console app already, do nothing */
 #ifndef WIN32_CONSOLE_APP
@@ -404,7 +404,7 @@ void subsurface_console_init(void)
 #endif
 }
 
-void subsurface_console_exit(void)
+void subsurface_console_exit()
 {
 #ifndef WIN32_CONSOLE_APP
 	/* close handles */
diff --git a/desktop-widgets/mainwindow.cpp b/desktop-widgets/mainwindow.cpp
index d5587c0f4..65a331584 100644
--- a/desktop-widgets/mainwindow.cpp
+++ b/desktop-widgets/mainwindow.cpp
@@ -1184,7 +1184,7 @@ void MainWindow::recentFileTriggered(bool)
 	loadFiles(std::vector<std::string> { filename.toStdString() });
 }
 
-int MainWindow::file_save_as(void)
+int MainWindow::file_save_as()
 {
 	QString filename;
 	std::string default_filename = existing_filename;
@@ -1232,7 +1232,7 @@ int MainWindow::file_save_as(void)
 	return 0;
 }
 
-int MainWindow::file_save(void)
+int MainWindow::file_save()
 {
 	const char *current_default;
 	bool is_cloud = false;
diff --git a/desktop-widgets/printdialog.cpp b/desktop-widgets/printdialog.cpp
index 8abaac4a2..885d8d321 100644
--- a/desktop-widgets/printdialog.cpp
+++ b/desktop-widgets/printdialog.cpp
@@ -184,7 +184,7 @@ void PrintDialog::createPrinterObj()
 	}
 }
 
-void PrintDialog::previewClicked(void)
+void PrintDialog::previewClicked()
 {
 	createPrinterObj();
 	QPrintPreviewDialog previewDialog(qprinter, this, Qt::Window
@@ -194,7 +194,7 @@ void PrintDialog::previewClicked(void)
 	previewDialog.exec();
 }
 
-void PrintDialog::exportHtmlClicked(void)
+void PrintDialog::exportHtmlClicked()
 {
 	createPrinterObj();
 	QString saveFileName = printOptions.p_template;
@@ -212,7 +212,7 @@ void PrintDialog::exportHtmlClicked(void)
 	}
 }
 
-void PrintDialog::printClicked(void)
+void PrintDialog::printClicked()
 {
 	createPrinterObj();
 	QPrintDialog printDialog(qprinter, this);