diff --git a/include/polarssl/cipher.h b/include/polarssl/cipher.h
index d4231ff..b520d92 100644
--- a/include/polarssl/cipher.h
+++ b/include/polarssl/cipher.h
@@ -107,6 +107,7 @@
 typedef enum {
     POLARSSL_PADDING_PKCS7 = 0,     /**< PKCS7 padding (default) */
     POLARSSL_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding  */
+    POLARSSL_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding      */
 } cipher_padding_t;
 
 typedef enum {