diff --git a/boot/fdt_support.c b/boot/fdt_support.c
index 2392027..2c39b2d 100644
--- a/boot/fdt_support.c
+++ b/boot/fdt_support.c
@@ -321,7 +321,7 @@
  * board_fdt_chosen_bootargs - boards may override this function to use
  *                             alternative kernel command line arguments
  */
-__weak char *board_fdt_chosen_bootargs(void)
+__weak const char *board_fdt_chosen_bootargs(void)
 {
 	return env_get("bootargs");
 }
@@ -331,7 +331,7 @@
 	struct abuf buf = {};
 	int   nodeoffset;
 	int   err;
-	char  *str;		/* used to set string properties */
+	const char *str;		/* used to set string properties */
 
 	err = fdt_check_header(fdt);
 	if (err < 0) {
diff --git a/include/fdt_support.h b/include/fdt_support.h
index ed4f5ba..f481881 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -236,7 +236,7 @@
  *
  * Return: pointer to kernel command line arguments in memory
  */
-char *board_fdt_chosen_bootargs(void);
+const char *board_fdt_chosen_bootargs(void);
 
 /*
  * The keystone2 SOC requires all 32 bit aliased addresses to be converted