diff --git a/libxbc/libxbc.c b/libxbc/libxbc.c
index 6e47dee..d80ac11 100644
--- a/libxbc/libxbc.c
+++ b/libxbc/libxbc.c
@@ -53,7 +53,7 @@
 /*
  * Add a string of boot config parameters to memory appended by the trailer.
  */
-int32_t addBootConfigParameters(char* params, uint32_t params_size,
+int32_t addBootConfigParameters(const char* params, uint32_t params_size,
     uint64_t bootconfig_start_addr, uint32_t bootconfig_size) {
     if (!params || !bootconfig_start_addr) {
         return -1;
diff --git a/libxbc/libxbc.h b/libxbc/libxbc.h
index 0bee548..7f5b311 100644
--- a/libxbc/libxbc.h
+++ b/libxbc/libxbc.h
@@ -35,7 +35,7 @@
  * @param bootconfig_size size of the current bootconfig section in bytes.
  * @return number of bytes added to the boot config section. -1 for error.
  */
-int addBootConfigParameters(char *params, uint32_t params_size,
+int addBootConfigParameters(const char *params, uint32_t params_size,
                             uint64_t bootconfig_start_addr,
                             uint32_t bootconfig_size);