diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 2d2c67af0..37337d504 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -3649,6 +3649,8 @@
  *
  * If defined, this is a header which will be included after
  * `"mbedtls/mbedtls_config.h"` or #MBEDTLS_CONFIG_FILE.
+ * This allows you to modify the default configuration, including the ability
+ * to undefine options that are enabled by default.
  *
  * This macro is expanded after an <tt>\#include</tt> directive. This is a popular but
  * non-standard feature of the C language, so this feature is only available
@@ -3682,6 +3684,8 @@
  *
  * If defined, this is a header which will be included after
  * `"psa/crypto_config.h"` or #MBEDTLS_PSA_CRYPTO_CONFIG_FILE.
+ * This allows you to modify the default configuration, including the ability
+ * to undefine options that are enabled by default.
  *
  * This macro is expanded after an <tt>\#include</tt> directive. This is a popular but
  * non-standard feature of the C language, so this feature is only available