diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index 96c96a3..3bad559 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -260,9 +260,12 @@
 int mbedtls_platform_random_delay( size_t num );
 
 /**
- * \brief       This function does nothing, but can be inserted between
- *              successive reads to a volatile local variable to prevent
- *              compilers from optimizing them away.
+ * \brief       This function can be inserted between successive reads to a
+ *              volatile local variable to prevent compilers from optimizing
+ *              them away. In addition, this function will spent a small random
+ *              time in a busy loop as a counter-measure to fault injection
+ *              attack.
+ *
  */
 void mbedtls_platform_enforce_volatile_reads( void );