diff --git a/cmd/ethkey/README.md b/cmd/ethkey/README.md
index 689d2f009d..48d3c9e9b7 100644
--- a/cmd/ethkey/README.md
+++ b/cmd/ethkey/README.md
@@ -25,12 +25,20 @@ make sure to use this feature with great caution!
 
 Sign the message with a keyfile.
 It is possible to refer to a file containing the message.
+To sign a message contained in a file, use the `--msgfile` flag.
 
 
 ### `ethkey verifymessage <address> <signature> <message/file>`
 
 Verify the signature of the message.
 It is possible to refer to a file containing the message.
+To sign a message contained in a file, use the --msgfile flag.
+
+
+### `ethkey changepassphrase <keyfile>`
+
+Change the passphrase of a keyfile.
+use the `--newpasswordfile` to point to the new password file.
 
 
 ## Passphrases
@@ -39,3 +47,7 @@ For every command that uses a keyfile, you will be prompted to provide the
 passphrase for decrypting the keyfile.  To avoid this message, it is possible
 to pass the passphrase by using the `--passwordfile` flag pointing to a file that
 contains the passphrase.
+
+## JSON
+
+In case you need to output the result in a JSON format, you shall by using the `--json` flag.