diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 4ee5920..4ac141e 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -655,6 +655,16 @@
 //#define MBEDTLS_AES_SCA_COUNTERMEASURES
 
 /**
+ * \def MBEDTLS_FI_COUNTERMEASURES
+ *
+ * Add countermeasures against possible  FI attack.
+ *
+ * Uncommenting this macro inrease sode size and slow performence,
+ * it peforms double calls and double result checks of some crypto functions
+ */
+//#define MBEDTLS_FI_COUNTERMEASURES
+
+/**
  * \def MBEDTLS_CAMELLIA_SMALL_MEMORY
  *
  * Use less ROM for the Camellia implementation (saves about 768 bytes).