diff --git a/cores/esp32/HardwareSerial.cpp b/cores/esp32/HardwareSerial.cpp
index 7abce142..c59da847 100644
--- a/cores/esp32/HardwareSerial.cpp
+++ b/cores/esp32/HardwareSerial.cpp
@@ -174,9 +174,9 @@ void HardwareSerial::flush(bool txOnly)
     uartFlushTxOnly(_uart, txOnly);
 }
 
-size_t HardwareSerial::write(std::string_view buf)
+size_t HardwareSerial::write(std::basic_string_view<unsigned char> buf)
 {
-    uartWriteBuf(_uart, (const uint8_t *)buf.data(), buf.size());
+    uartWriteBuf(_uart, buf.data(), buf.size());
     return buf.size();
 }
 uint32_t  HardwareSerial::baudRate()
diff --git a/cores/esp32/HardwareSerial.h b/cores/esp32/HardwareSerial.h
index 68fe361c..3954b0b6 100644
--- a/cores/esp32/HardwareSerial.h
+++ b/cores/esp32/HardwareSerial.h
@@ -70,7 +70,8 @@ public:
     }
     void flush(void);
     void flush( bool txOnly);
-    size_t write(std::string_view buf);
+    size_t write(std::string_view buf) { return write(std::basic_string_view<unsigned char>{reinterpret_cast<const unsigned char *>(buf.data()), buf.size()}); }
+    size_t write(std::basic_string_view<unsigned char> buf);
     uint32_t baudRate();
     operator bool() const;