diff --git a/aes.c b/aes.c
index 13c0a5f..d22c8a8 100644
--- a/aes.c
+++ b/aes.c
@@ -1,6 +1,7 @@
 /*
 
-This is an implementation of the AES128 algorithm, specifically ECB and CBC mode.
+This is an implementation of the AES algorithm, specifically ECB and CBC mode.
+Block size can be chosen in aes.h - available choices are AES128, AES192, AES256.
 
 The implementation is verified against the test vectors in:
   National Institute of Standards and Technology Special Publication 800-38A 2001 ED
@@ -26,6 +27,7 @@ ECB-AES128
 
 NOTE:   String length must be evenly divisible by 16byte (str_len % 16 == 0)
         You should pad the end of the string with zeros if this is not the case.
+        For AES192/256 the block size is proportionally larger.
 
 */