diff --git a/changes/bug4647 b/changes/bug4647
index 2ad08fec31..162a69c42e 100644
--- a/changes/bug4647
+++ b/changes/bug4647
@@ -6,6 +6,6 @@
       names as command-line options. Fixes bugs 4647 and 9578; bugfix on
       0.0.9pre5.
 
-
-
+    - No longer allow 'tor --hash-password' with no arguments. Fixes bug
+      9573; bugfix on 0.0.9pre5.
 
diff --git a/doc/tor.1.txt b/doc/tor.1.txt
index ec00c093a2..29a05d2e2a 100644
--- a/doc/tor.1.txt
+++ b/doc/tor.1.txt
@@ -46,7 +46,7 @@ COMMAND-LINE OPTIONS
     configuration file, and by those on the command line. (Default:
     @CONFDIR@/torrc-defaults.)
 
-**--hash-password**::
+**--hash-password** __PASSWORD__::
     Generates a hashed password for control port access.
 
 **--list-fingerprint**::
diff --git a/src/or/config.c b/src/or/config.c
index cda769db8c..7f1b77c4b1 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -1867,7 +1867,7 @@ config_parse_commandline(int argc, char **argv, int ignore_errors,
     }
 
     if (want_arg && i == argc-1) {
-      if (!strcmp(argv[i],"--hash-password") || ignore_errors) {
+      if (ignore_errors) {
         arg = strdup("");
       } else {
         log_warn(LD_CONFIG,"Command-line option '%s' with no value. Failing.",