diff --git a/docs/c-api/net.h/mg_time.md b/docs/c-api/net.h/mg_time.md
index 73b5e38705025c86a1f31d7749fc4ec82ab9d647..ec93b89726de8c85db2213c3c5f4e9e12c880d5a 100644
--- a/docs/c-api/net.h/mg_time.md
+++ b/docs/c-api/net.h/mg_time.md
@@ -3,7 +3,7 @@ title: "mg_time()"
 decl_name: "mg_time"
 symbol_kind: "func"
 signature: |
-  double mg_time();
+  double mg_time(void);
 ---
 
 A sub-second precision version of time(). 
diff --git a/examples/CC3200/ccs/MG_hello/main.c b/examples/CC3200/ccs/MG_hello/main.c
index 0124b416f83c6d04d44e0cadd326dd80318efb88..2778979b2ba825c68b177cf107b19a3b7da9174b 100644
--- a/examples/CC3200/ccs/MG_hello/main.c
+++ b/examples/CC3200/ccs/MG_hello/main.c
@@ -186,7 +186,7 @@ static void mg_init(struct mg_mgr *mgr) {
 extern void (*const g_pfnVectors[])(void);
 #endif
 
-int main() {
+int main(void) {
 #ifndef USE_TIRTOS
   MAP_IntVTableBaseSet((unsigned long) &g_pfnVectors[0]);
 #endif
@@ -223,10 +223,10 @@ int main() {
 }
 
 /* These are FreeRTOS hooks for various life situations. */
-void vApplicationMallocFailedHook() {
+void vApplicationMallocFailedHook(void) {
 }
 
-void vApplicationIdleHook() {
+void vApplicationIdleHook(void) {
 }
 
 void vApplicationStackOverflowHook(OsiTaskHandle *th, signed char *tn) {
diff --git a/examples/CC3200/data.c b/examples/CC3200/data.c
index 8365d21fd7c616432202692dda6e018c3d5a3140..c47ff94bd51dc973dee38901815e457c16c4ca6e 100644
--- a/examples/CC3200/data.c
+++ b/examples/CC3200/data.c
@@ -47,7 +47,7 @@ void data_init_sensors(int tmp006_addr, int bm222_addr) {
   }
 }
 
-void data_collect() {
+void data_collect(void) {
   double volt = tmp006_read_sensor_voltage(s_tmp006_addr);
   double temp = tmp006_read_die_temp(s_tmp006_addr);
   if (volt != TMP006_INVALID_READING && temp != TMP006_INVALID_READING) {
diff --git a/examples/CC3200/data.h b/examples/CC3200/data.h
index e9e8cf9c2b36e931793c44f7ed8f17696e26083a..35be40f906203d0579a88c37a19c68f977ba073c 100644
--- a/examples/CC3200/data.h
+++ b/examples/CC3200/data.h
@@ -8,7 +8,7 @@
 
 #include "mongoose.h"
 
-void data_collect();
+void data_collect(void);
 void data_init_sensors(int tmp006_addr, int bm222_addr);
 void data_conn_handler(struct mg_connection *nc, int ev, void *p);
 
diff --git a/examples/CC3200/main.c b/examples/CC3200/main.c
index 676e07031db86b0f526bad4bdcc92265c1ce5514..21ea4d1f688ae6ef6e74d7cc4a5fe8ec1ea6d650 100644
--- a/examples/CC3200/main.c
+++ b/examples/CC3200/main.c
@@ -222,7 +222,7 @@ static void mg_init(struct mg_mgr *mgr) {
 extern void (*const g_pfnVectors[])(void);
 #endif
 
-int main() {
+int main(void) {
 #ifndef USE_TIRTOS
   MAP_IntVTableBaseSet((unsigned long) &g_pfnVectors[0]);
 #endif
@@ -274,10 +274,10 @@ int main() {
 }
 
 /* These are FreeRTOS hooks for various life situations. */
-void vApplicationMallocFailedHook() {
+void vApplicationMallocFailedHook(void) {
 }
 
-void vApplicationIdleHook() {
+void vApplicationIdleHook(void) {
 }
 
 void vApplicationStackOverflowHook(OsiTaskHandle *th, signed char *tn) {
diff --git a/examples/CC3200/wifi.h b/examples/CC3200/wifi.h
index 982fa821ba64da1f160b0093cf417beebf1053b2..70715b43c2fb448159e41632e16bf42b485c8fa8 100644
--- a/examples/CC3200/wifi.h
+++ b/examples/CC3200/wifi.h
@@ -10,6 +10,6 @@
 
 bool wifi_setup_ap(const char *ssid, const char *pass, int channel);
 bool wifi_setup_sta(const char *ssid, const char *pass);
-void stop_nwp();
+void stop_nwp(void);
 
 #endif /* CS_MONGOOSE_EXAMPLES_CC3200_WIFI_H_ */
diff --git a/examples/ESP8266_RTOS/user/user_main.c b/examples/ESP8266_RTOS/user/user_main.c
index cbda034d8d069510090e7bd2320c336a6e5409d3..892c2a52a58e80a37efc1583be0e97eec1fe6e6f 100644
--- a/examples/ESP8266_RTOS/user/user_main.c
+++ b/examples/ESP8266_RTOS/user/user_main.c
@@ -54,7 +54,7 @@ void ev_handler(struct mg_connection *nc, int ev, void *p) {
   }
 }
 
-void setup_ap() {
+void setup_ap(void) {
   int off = 0;
   struct ip_info info;
   struct softap_config cfg;
diff --git a/examples/coap_server/coap_server.c b/examples/coap_server/coap_server.c
index bfe4b8cdc440c350bf311bcb0dd1a83aa8bf9f1e..45e59e20305cc77a9ea51dca267d5c6a13695a01 100644
--- a/examples/coap_server/coap_server.c
+++ b/examples/coap_server/coap_server.c
@@ -42,7 +42,7 @@ static void coap_handler(struct mg_connection *nc, int ev, void *p) {
   }
 }
 
-int main() {
+int main(void) {
   struct mg_mgr mgr;
   struct mg_connection *nc;
 
diff --git a/examples/cookie_auth/cookie_auth.c b/examples/cookie_auth/cookie_auth.c
index b2484258be917587a755e59c26b17cae7f82733e..2c0811237a56fc78e95237942040801246f12d99 100644
--- a/examples/cookie_auth/cookie_auth.c
+++ b/examples/cookie_auth/cookie_auth.c
@@ -183,7 +183,7 @@ static void logout_handler(struct mg_connection *nc, int ev, void *p) {
 }
 
 /* Cleans up sessions that have been idle for too long. */
-void check_sessions() {
+void check_sessions(void) {
   double threshold = mg_time() - SESSION_TTL;
   for (int i = 0; i < NUM_SESSIONS; i++) {
     struct session *s = &s_sessions[i];
diff --git a/examples/simple_crawler/simple_crawler.c b/examples/simple_crawler/simple_crawler.c
index a556de9301880ef27f1a526aa2c05aeb6c8979f3..1ae83f34eea3d3dedf902a464ffd851aeb8e83d1 100644
--- a/examples/simple_crawler/simple_crawler.c
+++ b/examples/simple_crawler/simple_crawler.c
@@ -40,7 +40,7 @@ static void event_handler(struct mg_connection *nc, int event, void *data) {
   }
 }
 
-int main() {
+int main(void) {
   struct mg_mgr mgr;
 
   mg_mgr_init(&mgr, NULL);
diff --git a/mongoose.c b/mongoose.c
index 3a38a1976e1000a24d3ee942c03714e27cfc6c0e..28efbd456a446f37b5b05ba7604f3ead23c16cdf 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -672,7 +672,7 @@ typedef int cs_dirent_dummy;
 #include <windows.h>
 #endif
 
-double cs_time() {
+double cs_time(void) {
   double now;
 #ifndef _WIN32
   struct timeval tv;
@@ -2721,7 +2721,7 @@ struct mg_connection *mg_add_sock(struct mg_mgr *s, sock_t sock,
   return mg_add_sock_opt(s, sock, callback, opts);
 }
 
-double mg_time() {
+double mg_time(void) {
   return cs_time();
 }
 #ifdef MG_MODULE_LINES
@@ -10408,7 +10408,7 @@ int mkdir(const char *path, mode_t mode) {
 }
 #endif
 
-int sl_fs_init() {
+int sl_fs_init(void) {
   int ret = 1;
 #ifdef __TI_COMPILER_VERSION__
 #ifdef MG_FS_SLFS
diff --git a/mongoose.h b/mongoose.h
index ca7d5ebc8578440f718ebef8a4e050e8561ab14c..6179d319b83a6b3571a721a9858bc2a5731192f5 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -788,7 +788,7 @@ bool mg_start_task(int priority, int stack_size, mg_init_cb mg_init);
 
 void mg_run_in_task(void (*cb)(struct mg_mgr *mgr, void *arg), void *cb_arg);
 
-int sl_fs_init();
+int sl_fs_init(void);
 
 void sl_restart_cb(struct mg_mgr *mgr);
 
@@ -814,7 +814,7 @@ extern "C" {
 #endif /* __cplusplus */
 
 /* Sub-second granularity time(). */
-double cs_time();
+double cs_time(void);
 
 #ifdef __cplusplus
 }
@@ -1631,7 +1631,7 @@ double mg_set_timer(struct mg_connection *c, double timestamp);
 /*
  * A sub-second precision version of time().
  */
-double mg_time();
+double mg_time(void);
 
 #ifdef __cplusplus
 }