diff --git a/Makefile b/Makefile
index 6ee049d9c..3101eb79e 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ CFG_DIR = $(BASE_DIR)/cfg
 
 LIBS = toxcore ncursesw libconfig libcurl
 
-CFLAGS ?= -std=c11 -pthread -Wall -Wpedantic -Wunused -fstack-protector-all -Wvla -Wno-missing-braces
+CFLAGS ?= -std=c11 -pthread -Wall -Wpedantic -Wunused -fstack-protector-all -Wvla -Wno-missing-braces -Wmissing-prototypes
 CFLAGS += '-DTOXICVER="$(VERSION)"' -DHAVE_WIDECHAR -D_XOPEN_SOURCE_EXTENDED -D_FILE_OFFSET_BITS=64
 CFLAGS += '-DPACKAGE_DATADIR="$(abspath $(DATADIR))"'
 CFLAGS += ${USER_CFLAGS}
diff --git a/src/audio_call.c b/src/audio_call.c
index 95112f78d..cce0766ef 100644
--- a/src/audio_call.c
+++ b/src/audio_call.c
@@ -132,7 +132,7 @@ ToxAV *init_audio(Toxic *toxic)
     return toxic->av;
 }
 
-void read_device_callback(const int16_t *captured, uint32_t size, void *data)
+static void read_device_callback(const int16_t *captured, uint32_t size, void *data)
 {
     UNUSED_VAR(size);
 
diff --git a/src/audio_device.c b/src/audio_device.c
index d0aaba637..a44ff8beb 100644
--- a/src/audio_device.c
+++ b/src/audio_device.c
@@ -661,7 +661,7 @@ DeviceError write_out(uint32_t device_idx, const int16_t *data, uint32_t sample_
  *
  * return normalized volume of buffer in range 0.0-100.0
  */
-float volume(int16_t *frame, uint32_t samples)
+static float volume(int16_t *frame, uint32_t samples)
 {
     float sum_of_squares = 0;
 
diff --git a/src/bootstrap.c b/src/bootstrap.c
index b01f1bb8d..74016531e 100644
--- a/src/bootstrap.c
+++ b/src/bootstrap.c
@@ -512,7 +512,7 @@ static int extract_node(const char *line, struct Node *node)
 }
 
 /* Loads the DHT nodeslist to memory from json encoded nodes file. */
-void *load_nodeslist_thread(void *data)
+static void *load_nodeslist_thread(void *data)
 {
 
     const Toxic *toxic = (Toxic *) data;
diff --git a/src/chat.c b/src/chat.c
index 5c9dafd08..28e64ad08 100644
--- a/src/chat.c
+++ b/src/chat.c
@@ -904,7 +904,7 @@ static void chat_onGroupInvite(ToxWindow *self, Toxic *toxic, uint32_t friendnum
 }
 
 #ifdef GAMES
-void chat_onGameInvite(ToxWindow *self, Toxic *toxic, uint32_t friend_number, const uint8_t *data, size_t length)
+static void chat_onGameInvite(ToxWindow *self, Toxic *toxic, uint32_t friend_number, const uint8_t *data, size_t length)
 {
     if (toxic == NULL || self == NULL) {
         return;
@@ -986,7 +986,7 @@ void chat_onGameInvite(ToxWindow *self, Toxic *toxic, uint32_t friend_number, co
 /* AV Stuff */
 #ifdef AUDIO
 
-void chat_onInvite(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
+static void chat_onInvite(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
 {
     UNUSED_VAR(state);
 
@@ -1018,7 +1018,7 @@ void chat_onInvite(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int st
     }
 }
 
-void chat_onRinging(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
+static void chat_onRinging(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
 {
     UNUSED_VAR(state);
 
@@ -1044,7 +1044,7 @@ void chat_onRinging(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int s
 #endif /* SOUND_NOTIFY */
 }
 
-void chat_onStarting(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
+static void chat_onStarting(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
 {
     UNUSED_VAR(state);
 
@@ -1070,7 +1070,7 @@ void chat_onStarting(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int
 #endif /* SOUND_NOTIFY */
 }
 
-void chat_onError(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
+static void chat_onError(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
 {
     UNUSED_VAR(state);
 
@@ -1090,7 +1090,7 @@ void chat_onError(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int sta
 #endif /* SOUND_NOTIFY */
 }
 
-void chat_onStart(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
+static void chat_onStart(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
 {
     UNUSED_VAR(state);
 
@@ -1116,7 +1116,7 @@ void chat_onStart(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int sta
 #endif /* SOUND_NOTIFY */
 }
 
-void chat_onCancel(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
+static void chat_onCancel(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
 {
     UNUSED_VAR(state);
 
@@ -1137,7 +1137,7 @@ void chat_onCancel(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int st
 #endif /* SOUND_NOTIFY */
 }
 
-void chat_onReject(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
+static void chat_onReject(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
 {
     UNUSED_VAR(state);
 
@@ -1157,7 +1157,7 @@ void chat_onReject(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int st
 #endif /* SOUND_NOTIFY */
 }
 
-void chat_onEnd(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
+static void chat_onEnd(ToxWindow *self, Toxic *toxic, uint32_t friend_number, int state)
 {
     UNUSED_VAR(state);
 
@@ -1294,7 +1294,7 @@ static void send_action(ToxWindow *self, ChatContext *ctx, Toxic *toxic, char *a
 /*
  * Return true if input is recognized by handler
  */
-bool chat_onKey(ToxWindow *self, Toxic *toxic, wint_t key, bool ltr)
+static bool chat_onKey(ToxWindow *self, Toxic *toxic, wint_t key, bool ltr)
 {
     if (toxic == NULL || self == NULL) {
         return false;
diff --git a/src/game_base.c b/src/game_base.c
index c26d40e36..5a06bb934 100644
--- a/src/game_base.c
+++ b/src/game_base.c
@@ -731,7 +731,7 @@ static void game_update_state(GameData *game)
     }
 }
 
-void game_onDraw(ToxWindow *self, Toxic *toxic)
+static void game_onDraw(ToxWindow *self, Toxic *toxic)
 {
     UNUSED_VAR(toxic);   // Note: This function is not thread safe if we ever need to use `toxic`
 
@@ -787,7 +787,7 @@ void game_onDraw(ToxWindow *self, Toxic *toxic)
     game_draw_messages(game, true);
 }
 
-bool game_onKey(ToxWindow *self, Toxic *toxic, wint_t key, bool is_printable)
+static bool game_onKey(ToxWindow *self, Toxic *toxic, wint_t key, bool is_printable)
 {
     UNUSED_VAR(is_printable);
 
@@ -828,7 +828,7 @@ bool game_onKey(ToxWindow *self, Toxic *toxic, wint_t key, bool is_printable)
     return true;
 }
 
-void game_onInit(ToxWindow *self, Toxic *toxic)
+static void game_onInit(ToxWindow *self, Toxic *toxic)
 {
     UNUSED_VAR(toxic);
 
@@ -853,7 +853,7 @@ void game_onInit(ToxWindow *self, Toxic *toxic)
  * Byte 2-5: Game ID
  * Byte 6-*  Game data
  */
-void game_onPacket(ToxWindow *self, Toxic *toxic, uint32_t friendnumber, const uint8_t *data, size_t length)
+static void game_onPacket(ToxWindow *self, Toxic *toxic, uint32_t friendnumber, const uint8_t *data, size_t length)
 {
     UNUSED_VAR(toxic);
 
diff --git a/src/game_centipede.c b/src/game_centipede.c
index 8591ab97a..4eef52a94 100644
--- a/src/game_centipede.c
+++ b/src/game_centipede.c
@@ -849,7 +849,7 @@ static void cent_bullet_move(const GameData *game, CentState *state, TIME_MS cur
     }
 }
 
-void cent_bullet_spawn(CentState *state)
+static void cent_bullet_spawn(CentState *state)
 {
     Projectile *bullet = &state->bullet;
 
@@ -1505,7 +1505,7 @@ static void cent_mushrooms_draw(WINDOW *win, const CentState *state)
     }
 }
 
-void cent_cb_update_game_state(GameData *game, void *cb_data)
+static void cent_cb_update_game_state(GameData *game, void *cb_data)
 {
     CentState *state = (CentState *)cb_data;
 
@@ -1529,7 +1529,7 @@ void cent_cb_update_game_state(GameData *game, void *cb_data)
     cent_do_scorpion(game, state, cur_time);
 }
 
-void cent_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
+static void cent_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
 {
     CentState *state = (CentState *)cb_data;
 
@@ -1544,7 +1544,7 @@ void cent_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
     cent_centipede_draw(game, win, state);
 }
 
-void cent_cb_on_keypress(GameData *game, int key, void *cb_data)
+static void cent_cb_on_keypress(GameData *game, int key, void *cb_data)
 {
     CentState *state = (CentState *)cb_data;
 
@@ -1564,7 +1564,7 @@ void cent_cb_on_keypress(GameData *game, int key, void *cb_data)
     }
 }
 
-void cent_cb_pause(GameData *game, bool is_paused, void *cb_data)
+static void cent_cb_pause(GameData *game, bool is_paused, void *cb_data)
 {
     CentState *state = (CentState *)cb_data;
 
@@ -1581,7 +1581,7 @@ void cent_cb_pause(GameData *game, bool is_paused, void *cb_data)
     }
 }
 
-void cent_cb_kill(GameData *game, void *cb_data)
+static void cent_cb_kill(GameData *game, void *cb_data)
 {
     CentState *state = (CentState *)cb_data;
 
diff --git a/src/game_chess.c b/src/game_chess.c
index a53ca4492..bcf9deb35 100644
--- a/src/game_chess.c
+++ b/src/game_chess.c
@@ -1484,25 +1484,25 @@ static int chess_get_display_colour(ChessColour p_colour, int tile_colour)
     }
 }
 
-void chess_move_curs_up_left(ChessState *state)
+static void chess_move_curs_up_left(ChessState *state)
 {
     chess_move_curs_left(state);
     chess_move_curs_up(state);
 }
 
-void chess_move_curs_up_right(ChessState *state)
+static void chess_move_curs_up_right(ChessState *state)
 {
     chess_move_curs_right(state);
     chess_move_curs_up(state);
 }
 
-void chess_move_curs_down_left(ChessState *state)
+static void chess_move_curs_down_left(ChessState *state)
 {
     chess_move_curs_left(state);
     chess_move_curs_down(state);
 }
 
-void chess_move_curs_down_right(ChessState *state)
+static void chess_move_curs_down_right(ChessState *state)
 {
     chess_move_curs_right(state);
     chess_move_curs_down(state);
@@ -1714,7 +1714,7 @@ static void chess_draw_interface(const GameData *game, WINDOW *win, ChessState *
     chess_print_captured(game, win, state);
 }
 
-void chess_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
+static void chess_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
 {
     ChessState *state = (ChessState *)cb_data;
 
@@ -1730,7 +1730,7 @@ void chess_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
     chess_draw_interface(game, win, state);
 }
 
-void chess_cb_on_keypress(GameData *game, int key, void *cb_data)
+static void chess_cb_on_keypress(GameData *game, int key, void *cb_data)
 {
     ChessState *state = (ChessState *)cb_data;
 
@@ -1793,7 +1793,7 @@ void chess_cb_on_keypress(GameData *game, int key, void *cb_data)
     }
 }
 
-void chess_cb_kill(GameData *game, void *cb_data)
+static void chess_cb_kill(GameData *game, void *cb_data)
 {
     ChessState *state = (ChessState *)cb_data;
 
diff --git a/src/game_life.c b/src/game_life.c
index 4832bcc2c..b56a41445 100644
--- a/src/game_life.c
+++ b/src/game_life.c
@@ -346,7 +346,7 @@ static void life_start(GameData *game, LifeState *state)
     state->generation = 1;
 }
 
-void life_cb_update_game_state(GameData *game, void *cb_data)
+static void life_cb_update_game_state(GameData *game, void *cb_data)
 {
     LifeState *state = (LifeState *)cb_data;
 
@@ -357,7 +357,7 @@ void life_cb_update_game_state(GameData *game, void *cb_data)
     life_cycle(game, state);
 }
 
-void life_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
+static void life_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
 {
     LifeState *state = (LifeState *)cb_data;
 
@@ -442,7 +442,7 @@ static void life_move_curs_down_left(LifeState *state)
     life_move_curs_left(state);
 }
 
-void life_cb_on_keypress(GameData *game, int key, void *cb_data)
+static void life_cb_on_keypress(GameData *game, int key, void *cb_data)
 {
     LifeState *state = (LifeState *)cb_data;
 
@@ -555,7 +555,7 @@ static void life_free_cells(LifeState *state)
     free(state->cells);
 }
 
-void life_cb_pause(GameData *game, bool is_paused, void *cb_data)
+static void life_cb_pause(GameData *game, bool is_paused, void *cb_data)
 {
     LifeState *state = (LifeState *)cb_data;
 
@@ -566,7 +566,7 @@ void life_cb_pause(GameData *game, bool is_paused, void *cb_data)
     state->paused = is_paused;
 }
 
-void life_cb_kill(GameData *game, void *cb_data)
+static void life_cb_kill(GameData *game, void *cb_data)
 {
     LifeState *state = (LifeState *)cb_data;
 
diff --git a/src/game_snake.c b/src/game_snake.c
index d47a859df..3f6107bba 100644
--- a/src/game_snake.c
+++ b/src/game_snake.c
@@ -989,7 +989,7 @@ static void snake_draw_powerup(WINDOW *win, const SnakeState *state)
     }
 }
 
-void snake_cb_update_game_state(GameData *game, void *cb_data)
+static void snake_cb_update_game_state(GameData *game, void *cb_data)
 {
     SnakeState *state = (SnakeState *)cb_data;
 
@@ -1014,7 +1014,7 @@ void snake_cb_update_game_state(GameData *game, void *cb_data)
     }
 }
 
-void snake_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
+static void snake_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
 {
     SnakeState *state = (SnakeState *)cb_data;
 
@@ -1034,7 +1034,7 @@ void snake_cb_render_window(GameData *game, WINDOW *win, void *cb_data)
     snake_draw_snake(win, state->snake, state->snake_length);
 }
 
-void snake_cb_kill(GameData *game, void *cb_data)
+static void snake_cb_kill(GameData *game, void *cb_data)
 {
     SnakeState *state = (SnakeState *)cb_data;
 
@@ -1058,7 +1058,7 @@ void snake_cb_kill(GameData *game, void *cb_data)
     game_set_cb_on_pause(game, NULL, NULL);
 }
 
-void snake_cb_on_keypress(GameData *game, int key, void *cb_data)
+static void snake_cb_on_keypress(GameData *game, int key, void *cb_data)
 {
     SnakeState *state = (SnakeState *)cb_data;
 
@@ -1069,7 +1069,7 @@ void snake_cb_on_keypress(GameData *game, int key, void *cb_data)
     snake_set_key_press(state, key);
 }
 
-void snake_cb_pause(GameData *game, bool is_paused, void *cb_data)
+static void snake_cb_pause(GameData *game, bool is_paused, void *cb_data)
 {
     SnakeState *state = (SnakeState *)cb_data;
 
diff --git a/src/groupchats.c b/src/groupchats.c
index 4749a3253..4273505f1 100644
--- a/src/groupchats.c
+++ b/src/groupchats.c
@@ -1107,7 +1107,8 @@ static void groupchat_onGroupPrivacyState(ToxWindow *self, Toxic *toxic, uint32_
     write_to_log(ctx->log, c_config, tmp_event, "The founder", true);
 }
 
-void groupchat_onGroupVoiceState(ToxWindow *self, Toxic *toxic, uint32_t groupnumber, Tox_Group_Voice_State voice_state)
+static void groupchat_onGroupVoiceState(ToxWindow *self, Toxic *toxic, uint32_t groupnumber,
+                                        Tox_Group_Voice_State voice_state)
 {
     if (toxic == NULL || self == NULL) {
         return;
diff --git a/src/name_lookup.c b/src/name_lookup.c
index c1a5ba43a..032167497 100644
--- a/src/name_lookup.c
+++ b/src/name_lookup.c
@@ -233,7 +233,7 @@ static int process_response(struct Recv_Curl_Data *recv_data)
     return 0;
 }
 
-void *lookup_thread_func(void *data)
+static void *lookup_thread_func(void *data)
 {
     struct curl_slist *headers = NULL;
     CURL *c_handle = NULL;
diff --git a/src/notify.c b/src/notify.c
index 30f69c8cc..f4a4c4ed9 100644
--- a/src/notify.c
+++ b/src/notify.c
@@ -156,7 +156,7 @@ static void control_unlock(void)
 }
 
 #ifdef SOUND_NOTIFY
-bool is_playing(int source)
+static bool is_playing(int source)
 {
     int ready;
     alGetSourcei(source, AL_SOURCE_STATE, &ready);
@@ -190,7 +190,7 @@ static void m_open_device(const Client_Config *c_config)
     device_opened = true;
 }
 
-void m_close_device(void)
+static void m_close_device(void)
 {
     if (!device_opened) {
         return;
@@ -202,7 +202,7 @@ void m_close_device(void)
 }
 
 /* Terminate all sounds but wait for them to finish first */
-void graceful_clear(void)
+static void graceful_clear(void)
 {
     control_lock();
 
@@ -249,7 +249,7 @@ void graceful_clear(void)
     control_unlock();
 }
 
-void *do_playing(void *_p)
+static void *do_playing(void *_p)
 {
     UNUSED_VAR(_p);
 
@@ -327,7 +327,7 @@ void *do_playing(void *_p)
     pthread_exit(NULL);
 }
 
-int play_source(uint32_t source, uint32_t buffer, bool looping)
+static int play_source(uint32_t source, uint32_t buffer, bool looping)
 {
     int i = 0;
 
diff --git a/src/term_mplex.c b/src/term_mplex.c
index 1db2c608d..64bee346f 100644
--- a/src/term_mplex.c
+++ b/src/term_mplex.c
@@ -430,7 +430,7 @@ static void mplex_timer_handler(Toxic *toxic)
 /* Time in seconds between calls to mplex_timer_handler */
 #define MPLEX_TIMER_INTERVAL 5
 
-void *mplex_timer_thread(void *data)
+static void *mplex_timer_thread(void *data)
 {
     Toxic *toxic = (Toxic *) data;
 
diff --git a/src/toxic.c b/src/toxic.c
index b4d3ee117..02a98f21d 100644
--- a/src/toxic.c
+++ b/src/toxic.c
@@ -141,7 +141,7 @@ static void init_signal_catchers(void)
     signal(SIGSEGV, catch_SIGSEGV);
 }
 
-void kill_toxic(Toxic *toxic)
+static void kill_toxic(Toxic *toxic)
 {
     if (toxic == NULL) {
         return;
@@ -233,8 +233,8 @@ static const char *tox_log_level_show(Tox_Log_Level level)
     return "<invalid>";
 }
 
-void cb_toxcore_logger(Tox *tox, TOX_LOG_LEVEL level, const char *file, uint32_t line, const char *func,
-                       const char *message, void *user_data)
+static void cb_toxcore_logger(Tox *tox, TOX_LOG_LEVEL level, const char *file, uint32_t line, const char *func,
+                              const char *message, void *user_data)
 {
     UNUSED_VAR(tox);
 
@@ -1244,7 +1244,7 @@ static void poll_interface_refresh_flag(void)
 /* How often we refresh windows that aren't focused */
 #define INACTIVE_WIN_REFRESH_RATE 10
 
-void *thread_winref(void *data)
+static void *thread_winref(void *data)
 {
     Toxic *toxic = (Toxic *) data;
 
@@ -1273,7 +1273,7 @@ void *thread_winref(void *data)
     }
 }
 
-void *thread_cqueue(void *data)
+static void *thread_cqueue(void *data)
 {
     Toxic *toxic = (Toxic *) data;
 
@@ -1299,7 +1299,7 @@ void *thread_cqueue(void *data)
 }
 
 #ifdef AUDIO
-void *thread_av(void *data)
+static void *thread_av(void *data)
 {
     ToxAV *av = (ToxAV *) data;
 
diff --git a/src/video_call.c b/src/video_call.c
index 69c4e888d..d9e4eaf93 100644
--- a/src/video_call.c
+++ b/src/video_call.c
@@ -101,8 +101,8 @@ void terminate_video(void)
     terminate_video_devices();
 }
 
-void read_video_device_callback(Toxic *toxic, int16_t width, int16_t height, const uint8_t *y, const uint8_t *u,
-                                const uint8_t *v, void *data)
+static void read_video_device_callback(Toxic *toxic, int16_t width, int16_t height, const uint8_t *y, const uint8_t *u,
+                                       const uint8_t *v, void *data)
 {
     if (toxic == NULL) {
         return;
@@ -132,10 +132,10 @@ void read_video_device_callback(Toxic *toxic, int16_t width, int16_t height, con
     }
 }
 
-void write_video_device_callback(uint32_t friend_number, uint16_t width, uint16_t height,
-                                 uint8_t const *y, uint8_t const *u, uint8_t const *v,
-                                 int32_t ystride, int32_t ustride, int32_t vstride,
-                                 void *user_data)
+static void write_video_device_callback(uint32_t friend_number, uint16_t width, uint16_t height,
+                                        uint8_t const *y, uint8_t const *u, uint8_t const *v,
+                                        int32_t ystride, int32_t ustride, int32_t vstride,
+                                        void *user_data)
 {
     UNUSED_VAR(friend_number);
 
@@ -246,7 +246,7 @@ void callback_recv_video_end(uint32_t friend_number)
     close_video_device(vdt_output, this_call->vout_idx);
     this_call->vout_idx = -1;
 }
-void callback_video_starting(Toxic *toxic, uint32_t friend_number)
+static void callback_video_starting(Toxic *toxic, uint32_t friend_number)
 {
     Call *this_call = &CallControl.calls[friend_number];