diff --git a/library/platform_util.c b/library/platform_util.c
index 9d7323b3a4..9c18dd502a 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -147,8 +147,8 @@ void (*mbedtls_test_hook_test_fail)( const char *, int, const char *);
  * Provide external definitions of some inline functions so that the compiler
  * has the option to not inline them
  */
-extern inline void mbedtls_xor( unsigned char *r, unsigned char const *a, unsigned char const *b, size_t n );
+extern inline void mbedtls_xor( unsigned char *r, const unsigned char *a, const unsigned char *b, size_t n );
 
-extern inline uint32_t mbedtls_get_unaligned_uint32( void const *p );
+extern inline uint32_t mbedtls_get_unaligned_uint32( const void *p );
 
 extern inline void mbedtls_put_unaligned_uint32( void *p, uint32_t x );