diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 709f6cf0f..09379a094 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -501,6 +501,13 @@
  */
 #define MBEDTLS_CIPHER_MODE_CBC
 
+/**
+ * \def MBEDTLS_CIPHER_MODE_XEX
+ *
+ * Enable Xor-encrypt-xor mode (XEX) for symmetric ciphers.
+ */
+#define MBEDTLS_CIPHER_MODE_XEX
+
 /**
  * \def MBEDTLS_CIPHER_MODE_OFB
  *