diff --git a/components/esp8266/include/esp_libc.h b/components/esp8266/include/esp_libc.h
index 98106730..92467def 100644
--- a/components/esp8266/include/esp_libc.h
+++ b/components/esp8266/include/esp_libc.h
@@ -25,52 +25,16 @@
 #ifndef __ESP_LIBC_H__
 #define __ESP_LIBC_H__
 
+#include <stdint.h>
+#include <stddef.h>
+#include <stdio.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-char *strcpy(char *dst, const char *src);
-char *strncpy(char *dst, const char *src, size_t n);
-int strcmp(const char *s1, const char *s2);
-int strncmp(const char *s1, const char *s2, size_t n);
-size_t strlen(const char *s);
-char *strstr(const char *s1, const char *s2);
-char *strcat(char *dst, const char *src);
-char *strncat(char *dst, const char *src, size_t count);
-size_t strspn(const char *s, const char *accept);
-size_t strcspn(const char *s, const char *reject);
-char *strtok_r(char *s, const char *delim, char **ptrptr);
-char *strtok(char *s, const char *delim);
-char *strrchr(const char *s, int c);
-char *strdup(const char *s);
-char *strchr(const char *s, int c);
-long strtol(const char *str, char **endptr, int base);
-
-void bzero(void *s, size_t n);
-
-void *memcpy(void *dst, const void *src, size_t n);
-void *memset(void *dst, int c, size_t n);
-int memcmp(const void *m1, const void *m2, size_t n);
-void *memmove(void *dst, const void *src, size_t n);
-
-int rand(void);
-
-int printf(const char *format, ...);
-int sprintf(char *out, const char *format, ...);
-int snprintf(char *buf, unsigned int count, const char *format, ...);
-int puts(const char *str);
-
-void *malloc(size_t n);
-void free(void *p);
-void *calloc(size_t c, size_t n);
-void *zalloc(size_t n);
-void *realloc(void *p, size_t n);
-
-int atoi(const char *s);
-long atol(const char *s);
-
-unsigned long os_random(void);
-int os_get_random(unsigned char *buf, size_t len);
+uint32_t os_random(void);
+int32_t os_get_random(unsigned char *buf, size_t len);
 
 #ifndef os_printf
 #define os_printf   printf
diff --git a/components/freertos/port/esp8266/heap_5.c b/components/freertos/port/esp8266/heap_5.c
index aff13eec..78945ec4 100644
--- a/components/freertos/port/esp8266/heap_5.c
+++ b/components/freertos/port/esp8266/heap_5.c
@@ -106,6 +106,7 @@
  *
  */
 #include <stdlib.h>
+#include <string.h>
 
 /* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
 all the API functions to use the MPU wrappers.  That should only be done when
diff --git a/components/lwip/apps/dhcpserver/dhcpserver.c b/components/lwip/apps/dhcpserver/dhcpserver.c
index dfc56dcd..3360b46b 100644
--- a/components/lwip/apps/dhcpserver/dhcpserver.c
+++ b/components/lwip/apps/dhcpserver/dhcpserver.c
@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <string.h>
+#include <strings.h>
+
 #include "esp_common.h"
 #include "sdkconfig.h"
 #include "lwip/inet.h"
diff --git a/components/lwip/port/esp8266/freertos/sys_arch.c b/components/lwip/port/esp8266/freertos/sys_arch.c
index a238cb6c..191e4453 100644
--- a/components/lwip/port/esp8266/freertos/sys_arch.c
+++ b/components/lwip/port/esp8266/freertos/sys_arch.c
@@ -32,6 +32,8 @@
 
 /* lwIP includes. */
 
+#include <stdlib.h>
+
 #include "lwip/debug.h"
 #include "lwip/def.h"
 #include "lwip/sys.h"
diff --git a/components/lwip/port/esp8266/netif/ethernetif.c b/components/lwip/port/esp8266/netif/ethernetif.c
index c30f7478..2f588fdf 100644
--- a/components/lwip/port/esp8266/netif/ethernetif.c
+++ b/components/lwip/port/esp8266/netif/ethernetif.c
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <string.h>
+
 #include "lwip/pbuf.h"
 #include "lwip/ethip6.h"
 #include "netif/etharp.h"
diff --git a/components/mqtt/paho/MQTTClient-C/src/FreeRTOS/MQTTFreeRTOS.c b/components/mqtt/paho/MQTTClient-C/src/FreeRTOS/MQTTFreeRTOS.c
index 9664270f..5ed7b037 100755
--- a/components/mqtt/paho/MQTTClient-C/src/FreeRTOS/MQTTFreeRTOS.c
+++ b/components/mqtt/paho/MQTTClient-C/src/FreeRTOS/MQTTFreeRTOS.c
@@ -15,7 +15,10 @@
  *    Ian Craggs - convert to FreeRTOS
  *******************************************************************************/
 
-#include "lwip/netdb.h"
+#include <string.h>
+
+#include <netdb.h>
+
 #include "MQTTFreeRTOS.h"
 
 int ThreadStart(Thread* thread, void (*fn)(void*), void* arg)
diff --git a/components/tcpip_adapter/tcpip_adapter_wifi.c b/components/tcpip_adapter/tcpip_adapter_wifi.c
index 59f104a0..516b8fc1 100644
--- a/components/tcpip_adapter/tcpip_adapter_wifi.c
+++ b/components/tcpip_adapter/tcpip_adapter_wifi.c
@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <stdlib.h>
+#include <string.h>
+
 #include "lwip/netif.h"
 #include "lwip/tcpip.h"
 #include "lwip/dhcp.h"
@@ -589,4 +592,4 @@ struct netif* eagle_lwip_getif(uint8_t netif_index)
         TCPIP_ATAPTER_LOG("ERROR bad netif index:%d\n", netif_index);
         return NULL;
     }
-}
\ No newline at end of file
+}
diff --git a/examples/protocols/https_mbedtls/main/https_mbedtls_example_main.c b/examples/protocols/https_mbedtls/main/https_mbedtls_example_main.c
index 46aaa2f0..e28421bd 100644
--- a/examples/protocols/https_mbedtls/main/https_mbedtls_example_main.c
+++ b/examples/protocols/https_mbedtls/main/https_mbedtls_example_main.c
@@ -7,6 +7,9 @@
    CONDITIONS OF ANY KIND, either express or implied.
 */
 
+#include <string.h>
+#include <strings.h>
+
 #include "sdkconfig.h"
 
 #include "esp_misc.h"
@@ -19,7 +22,7 @@
 #include <sys/socket.h>
 #include <netdb.h>
 
-#include <lwip/apps/sntp.h>
+#include "lwip/apps/sntp.h"
 
 #include "mbedtls/platform.h"
 #include "mbedtls/net_sockets.h"
diff --git a/examples/protocols/mqtt/main/MQTTEcho.c b/examples/protocols/mqtt/main/MQTTEcho.c
index 7754d653..64c5bb61 100644
--- a/examples/protocols/mqtt/main/MQTTEcho.c
+++ b/examples/protocols/mqtt/main/MQTTEcho.c
@@ -15,6 +15,8 @@
  *******************************************************************************/
 
 #include <stddef.h>
+#include <stdio.h>
+#include <string.h>
 
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
diff --git a/examples/protocols/mqtt/main/user_main.c b/examples/protocols/mqtt/main/user_main.c
index 80b7d636..557c2392 100644
--- a/examples/protocols/mqtt/main/user_main.c
+++ b/examples/protocols/mqtt/main/user_main.c
@@ -7,6 +7,9 @@
    CONDITIONS OF ANY KIND, either express or implied.
 */
 
+#include <stdio.h>
+#include <strings.h>
+
 #include "esp_common.h"
 #include "user_config.h"
 
diff --git a/examples/protocols/openssl_client/main/openssl_client_example_main.c b/examples/protocols/openssl_client/main/openssl_client_example_main.c
index 866f9e0d..d30ad0bf 100644
--- a/examples/protocols/openssl_client/main/openssl_client_example_main.c
+++ b/examples/protocols/openssl_client/main/openssl_client_example_main.c
@@ -7,6 +7,9 @@
    CONDITIONS OF ANY KIND, either express or implied.
 */
 
+#include <string.h>
+#include <strings.h>
+
 #include "sdkconfig.h"
 
 #include "esp_misc.h"
@@ -338,4 +341,4 @@ void user_init(void)
     sprintf((char*)config.password, CONFIG_WIFI_PASSWORD);
     wifi_station_set_config(&config);
     wifi_set_event_handler_cb(wifi_event_handler_cb);
-}
\ No newline at end of file
+}
diff --git a/examples/protocols/openssl_demo/main/openssl_demo.c b/examples/protocols/openssl_demo/main/openssl_demo.c
index 4a70810e..ac63b6aa 100644
--- a/examples/protocols/openssl_demo/main/openssl_demo.c
+++ b/examples/protocols/openssl_demo/main/openssl_demo.c
@@ -8,6 +8,9 @@
 */
 
 #include <stddef.h>
+#include <string.h>
+#include <strings.h>
+
 #include "openssl_demo.h"
 #include "openssl/ssl.h"
 #include "freertos/FreeRTOS.h"
diff --git a/examples/protocols/openssl_demo/main/user_main.c b/examples/protocols/openssl_demo/main/user_main.c
index 3640b353..adc0b96d 100644
--- a/examples/protocols/openssl_demo/main/user_main.c
+++ b/examples/protocols/openssl_demo/main/user_main.c
@@ -7,6 +7,9 @@
    CONDITIONS OF ANY KIND, either express or implied.
 */
 
+#include <stdio.h>
+#include <string.h>
+
 #include "esp_common.h"
 #include "user_config.h"
 
diff --git a/examples/protocols/openssl_server/main/openssl_server_example_main.c b/examples/protocols/openssl_server/main/openssl_server_example_main.c
index e1d2caad..51e6949d 100644
--- a/examples/protocols/openssl_server/main/openssl_server_example_main.c
+++ b/examples/protocols/openssl_server/main/openssl_server_example_main.c
@@ -7,6 +7,10 @@
    CONDITIONS OF ANY KIND, either express or implied.
 */
 
+#include <stdio.h>
+#include <string.h>
+#include <strings.h>
+
 #include "sdkconfig.h"
 
 #include "esp_misc.h"
@@ -331,4 +335,4 @@ void user_init(void)
     sprintf((char*)config.password, CONFIG_WIFI_PASSWORD);
     wifi_station_set_config(&config);
     wifi_set_event_handler_cb(wifi_event_handler_cb);
-}
\ No newline at end of file
+}