diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 456ec66..8d7d631 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -2569,6 +2569,7 @@
 
 /* X509 options */
 //#define MBEDTLS_X509_MAX_INTERMEDIATE_CA   8   /**< Maximum number of intermediate CAs in a verification chain. */
+//#define MBEDTLS_X509_MAX_FILE_PATH_LEN     512 /**< Maximum length of a path/filename string in bytes including the null terminator character ('\0'). */
 
 /* \} name SECTION: Customisation configuration options */