diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index ce3a78d14..aa4ce230c 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -527,15 +527,15 @@
  *
  * Use only 128-bit keys in AES operations to save ROM.
  *
- * Uncommenting this macro removes support for AES operations that use 192-
+ * Uncomment this macro to remove support for AES operations that use 192-
  * or 256-bit keys.
  *
- * Tradeoff: Uncommenting this macro reduces the size of AES code by about 4%.
+ * Uncommenting this macro reduces the size of AES code by ~300 bytes
+ * on v8-M/Thumb2.
  *
  * Module:  library/aes.c
  *
  * Requires: MBEDTLS_AES_C
- *
  */
 //#define MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH