diff --git a/src/include/microhttpd.h b/src/include/microhttpd.h
index 1261ff88..d469b64d 100644
--- a/src/include/microhttpd.h
+++ b/src/include/microhttpd.h
@@ -1752,8 +1752,11 @@ enum MHD_OPTION
   /**
    * Memory pointer for the random values to be used by the Digest
    * Auth module. This option should be followed by two arguments.
-   * First an integer of type  `size_t` which specifies the size
+   * First an integer of type `size_t` which specifies the size
    * of the buffer pointed to by the second argument in bytes.
+   * The recommended size is between 8 and 32. If size is four or less
+   * then security could be lowered. Sizes more then 32 (or, probably
+   * more than 16 - debatable) will not increase security.
    * Note that the application must ensure that the buffer of the
    * second argument remains allocated and unmodified while the
    * daemon is running.