diff --git a/cores/esp32/HashBuilder.h b/cores/esp32/HashBuilder.h
index ce6f1f1af42..86013bd65a2 100644
--- a/cores/esp32/HashBuilder.h
+++ b/cores/esp32/HashBuilder.h
@@ -26,14 +26,10 @@ class HashBuilder : public HEXBuilder
     virtual ~HashBuilder() {}
     virtual void begin() = 0;
 
-    virtual void add(uint8_t* data, size_t len) = 0;
+    virtual void add(const uint8_t* data, size_t len) = 0;
     virtual void add(const char* data)
     {
-        add((uint8_t*)data, strlen(data));
-    }
-    virtual void add(char* data)
-    {
-        add((const char*)data);
+        add((const uint8_t*)data, strlen(data));
     }
     virtual void add(String data)
     {
@@ -41,10 +37,6 @@ class HashBuilder : public HEXBuilder
     }
 
     virtual void addHexString(const char* data) = 0;
-    virtual void addHexString(char* data)
-    {
-        addHexString((const char*)data);
-    }
     virtual void addHexString(String data)
     {
         addHexString(data.c_str());
diff --git a/cores/esp32/MD5Builder.cpp b/cores/esp32/MD5Builder.cpp
index 2198d06a27e..f27b2dc7846 100644
--- a/cores/esp32/MD5Builder.cpp
+++ b/cores/esp32/MD5Builder.cpp
@@ -27,7 +27,7 @@ void MD5Builder::begin(void)
     esp_rom_md5_init(&_ctx);
 }
 
-void MD5Builder::add(uint8_t * data, size_t len)
+void MD5Builder::add(const uint8_t * data, size_t len)
 {
     esp_rom_md5_update(&_ctx, data, len);
 }
diff --git a/cores/esp32/MD5Builder.h b/cores/esp32/MD5Builder.h
index 25dd8c49ec9..70f23cebb05 100644
--- a/cores/esp32/MD5Builder.h
+++ b/cores/esp32/MD5Builder.h
@@ -38,7 +38,7 @@ class MD5Builder : public HashBuilder
     void begin(void) override;
 
     using HashBuilder::add;
-    void add(uint8_t * data, size_t len) override;
+    void add(const uint8_t * data, size_t len) override;
 
     using HashBuilder::addHexString;
     void addHexString(const char * data) override;
diff --git a/cores/esp32/SHA1Builder.cpp b/cores/esp32/SHA1Builder.cpp
index 34f93271321..0f67d1086fd 100644
--- a/cores/esp32/SHA1Builder.cpp
+++ b/cores/esp32/SHA1Builder.cpp
@@ -230,7 +230,7 @@ void SHA1Builder::begin(void)
     memset(hash, 0x00, sizeof(hash));
 }
 
-void SHA1Builder::add(uint8_t* data, size_t len)
+void SHA1Builder::add(const uint8_t* data, size_t len)
 {
     size_t fill;
     uint32_t left;
diff --git a/cores/esp32/SHA1Builder.h b/cores/esp32/SHA1Builder.h
index 4a0dfe0c100..2ab876f6411 100644
--- a/cores/esp32/SHA1Builder.h
+++ b/cores/esp32/SHA1Builder.h
@@ -36,7 +36,7 @@ class SHA1Builder : public HashBuilder
     void begin() override;
 
     using HashBuilder::add;
-    void add(uint8_t* data, size_t len) override;
+    void add(const uint8_t* data, size_t len) override;
 
     using HashBuilder::addHexString;
     void addHexString(const char* data) override;