diff --git a/api/mraa/uart.h b/api/mraa/uart.h
index afdeeaa..091f136 100644
--- a/api/mraa/uart.h
+++ b/api/mraa/uart.h
@@ -61,7 +61,7 @@ mraa_uart_context mraa_uart_init(int uart);
  * @param path for example "/dev/ttyS0"
  * @return uart context or NULL
  */
-mraa_uart_context mraa_uart_init_raw(char* path);
+mraa_uart_context mraa_uart_init_raw(const char* path);
 
 /**
  * Flush the outbound data.
@@ -153,7 +153,7 @@ int mraa_uart_read(mraa_uart_context dev, char* buf, size_t length);
  * @param length maximum size of buffer
  * @return the number of bytes written, or -1 if an error occurred
  */
-int mraa_uart_write(mraa_uart_context dev, char* buf, size_t length);
+int mraa_uart_write(mraa_uart_context dev, const char* buf, size_t length);
 
 /**
  * Check to see if data is available on the device for reading
diff --git a/src/uart/uart.c b/src/uart/uart.c
index c14eb44..b7cd722 100644
--- a/src/uart/uart.c
+++ b/src/uart/uart.c
@@ -170,7 +170,7 @@ mraa_uart_init(int index)
 }
 
 mraa_uart_context
-mraa_uart_init_raw(char* path)
+mraa_uart_init_raw(const char* path)
 {
     mraa_uart_context dev = (mraa_uart_context) malloc(sizeof(struct _uart));
     if (dev == NULL) {
@@ -436,7 +436,7 @@ mraa_uart_read(mraa_uart_context dev, char* buf, size_t len)
 }
 
 int
-mraa_uart_write(mraa_uart_context dev, char* buf, size_t len)
+mraa_uart_write(mraa_uart_context dev, const char* buf, size_t len)
 {
     if (!dev) {
         syslog(LOG_ERR, "uart: write: context is NULL");