diff --git a/examples/01_hello_world/main/hello_world_main.c b/examples/01_hello_world/main/hello_world_main.c
index ad2c0acbbd..1ff190acef 100644
--- a/examples/01_hello_world/main/hello_world_main.c
+++ b/examples/01_hello_world/main/hello_world_main.c
@@ -27,6 +27,5 @@ void hello_task(void *pvParameter)
 void app_main()
 {
     nvs_flash_init();
-    system_init();
     xTaskCreate(&hello_task, "hello_task", 2048, NULL, 5, NULL);
 }
diff --git a/examples/02_blink/main/blink.c b/examples/02_blink/main/blink.c
index 6de0e1fa36..1e49e51b2f 100644
--- a/examples/02_blink/main/blink.c
+++ b/examples/02_blink/main/blink.c
@@ -43,6 +43,5 @@ void blink_task(void *pvParameter)
 void app_main()
 {
     nvs_flash_init();
-    system_init();
     xTaskCreate(&blink_task, "blink_task", 512, NULL, 5, NULL);
 }
diff --git a/examples/03_http_request/main/http_request_main.c b/examples/03_http_request/main/http_request_main.c
index 32f75c0da2..2c203f8394 100644
--- a/examples/03_http_request/main/http_request_main.c
+++ b/examples/03_http_request/main/http_request_main.c
@@ -175,7 +175,6 @@ static void http_get_task(void *pvParameters)
 void app_main()
 {
     nvs_flash_init();
-    system_init();
     initialise_wifi();
     xTaskCreate(&http_get_task, "http_get_task", 2048, NULL, 5, NULL);
 }
diff --git a/examples/04_https_request/main/https_request_main.c b/examples/04_https_request/main/https_request_main.c
index 7f302409d8..2ad56681d0 100644
--- a/examples/04_https_request/main/https_request_main.c
+++ b/examples/04_https_request/main/https_request_main.c
@@ -369,7 +369,6 @@ static void https_get_task(void *pvParameters)
 void app_main()
 {
     nvs_flash_init();
-    system_init();
     initialise_wifi();
     xTaskCreate(&https_get_task, "https_get_task", 8192, NULL, 5, NULL);
 }
diff --git a/examples/05_ble_adv/main/app_bt.c b/examples/05_ble_adv/main/app_bt.c
index 7f5dda5ec5..bfdd0b8c68 100755
--- a/examples/05_ble_adv/main/app_bt.c
+++ b/examples/05_ble_adv/main/app_bt.c
@@ -197,10 +197,9 @@ void bleAdvtTask(void *pvParameters)
     }
 }
 
-int app_main()
+void app_main()
 {
     bt_controller_init();
     xTaskCreatePinnedToCore(&bleAdvtTask, "bleAdvtTask", 2048, NULL, 5, NULL, 0);
-    return 0;
 }
 
diff --git a/examples/06_sntp/main/sntp_main.c b/examples/06_sntp/main/sntp_main.c
index 7f516625e3..83f33b9656 100644
--- a/examples/06_sntp/main/sntp_main.c
+++ b/examples/06_sntp/main/sntp_main.c
@@ -94,7 +94,6 @@ void app_main()
 static void obtain_time(void)
 {
     nvs_flash_init();
-    system_init();
     initialise_wifi();
     xEventGroupWaitBits(wifi_event_group, CONNECTED_BIT,
                         false, true, portMAX_DELAY);