diff --git a/aes.c b/aes.c
index c609c1f..7d5c986 100644
--- a/aes.c
+++ b/aes.c
@@ -27,7 +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.
+        For AES192/256 the key size is proportionally larger.
 
 */