diff --git a/cores/esp32/MD5Builder.cpp b/cores/esp32/MD5Builder.cpp
index f2168f4e6c4..c988abd1e05 100644
--- a/cores/esp32/MD5Builder.cpp
+++ b/cores/esp32/MD5Builder.cpp
@@ -19,7 +19,7 @@
 #include <Arduino.h>
 #include <MD5Builder.h>
 
-uint8_t hex_char_to_byte(uint8_t c)
+static uint8_t hex_char_to_byte(uint8_t c)
 {
     return  (c >= 'a' && c <= 'f') ? (c - ((uint8_t)'a' - 0xa)) :
             (c >= 'A' && c <= 'F') ? (c - ((uint8_t)'A' - 0xA)) :
@@ -28,13 +28,13 @@ uint8_t hex_char_to_byte(uint8_t c)
 
 void MD5Builder::begin(void)
 {
-    memset(_buf, 0x00, 16);
-    MD5Init(&_ctx);
+    memset(_buf, 0x00, ESP_ROM_MD5_DIGEST_LEN);
+    esp_rom_md5_init(&_ctx);
 }
 
 void MD5Builder::add(uint8_t * data, uint16_t len)
 {
-    MD5Update(&_ctx, data, len);
+    esp_rom_md5_update(&_ctx, data, len);
 }
 
 void MD5Builder::addHexString(const char * data)
@@ -82,7 +82,7 @@ bool MD5Builder::addStream(Stream & stream, const size_t maxLen)
         }
 
         // Update MD5 with buffer payload
-        MD5Update(&_ctx, buf, numBytesRead);
+        esp_rom_md5_update(&_ctx, buf, numBytesRead);
 
         // update available number of bytes
         maxLengthLeft -= numBytesRead;
@@ -94,24 +94,24 @@ bool MD5Builder::addStream(Stream & stream, const size_t maxLen)
 
 void MD5Builder::calculate(void)
 {
-    MD5Final(_buf, &_ctx);
+    esp_rom_md5_final(_buf, &_ctx);
 }
 
 void MD5Builder::getBytes(uint8_t * output)
 {
-    memcpy(output, _buf, 16);
+    memcpy(output, _buf, ESP_ROM_MD5_DIGEST_LEN);
 }
 
 void MD5Builder::getChars(char * output)
 {
-    for(uint8_t i = 0; i < 16; i++) {
+    for(uint8_t i = 0; i < ESP_ROM_MD5_DIGEST_LEN; i++) {
         sprintf(output + (i * 2), "%02x", _buf[i]);
     }
 }
 
 String MD5Builder::toString(void)
 {
-    char out[33];
+    char out[(ESP_ROM_MD5_DIGEST_LEN * 2) + 1];
     getChars(out);
     return String(out);
 }
diff --git a/cores/esp32/MD5Builder.h b/cores/esp32/MD5Builder.h
index 2588a74daec..4285384e384 100644
--- a/cores/esp32/MD5Builder.h
+++ b/cores/esp32/MD5Builder.h
@@ -23,25 +23,13 @@
 #include <Stream.h>
 
 #include "esp_system.h"
-#ifdef ESP_IDF_VERSION_MAJOR // IDF 4+
-#if CONFIG_IDF_TARGET_ESP32 // ESP32/PICO-D4
-#include "esp32/rom/md5_hash.h"
-#elif CONFIG_IDF_TARGET_ESP32S2
-#include "esp32s2/rom/md5_hash.h"
-#elif CONFIG_IDF_TARGET_ESP32C3
-#include "esp32c3/rom/md5_hash.h"
-#else 
-#error Target CONFIG_IDF_TARGET is not supported
-#endif
-#else // ESP32 Before IDF 4.0
-#include "rom/md5_hash.h"
-#endif
+#include "esp_rom_md5.h"
 
 class MD5Builder
 {
 private:
-    struct MD5Context _ctx;
-    uint8_t _buf[16];
+    md5_context_t _ctx;
+    uint8_t _buf[ESP_ROM_MD5_DIGEST_LEN];
 public:
     void begin(void);
     void add(uint8_t * data, uint16_t len);