diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 0444eb1..9689643 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -2492,6 +2492,7 @@
 
 /* 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'). */
 
 /**
  * Allow SHA-1 in the default TLS configuration for certificate signing.