diff --git a/README b/README
index 769c416d32..679a096b3b 100644
--- a/README
+++ b/README
@@ -901,6 +901,9 @@ sslserver: use an alternate server name for SSL URLs, like
            parameters correctly so that both the SSL server and the
            "normal" server can access the session cookie and
            preferably other cookies as well.
+shorturllength: Length of URL at which URLs in a message exceeding 140
+                characters will be sent to the user's chosen
+                shortening service.
 
 db
 --
diff --git a/lib/Shorturl_api.php b/lib/Shorturl_api.php
index fe106cb837..d1fc5eb6de 100644
--- a/lib/Shorturl_api.php
+++ b/lib/Shorturl_api.php
@@ -39,7 +39,7 @@ class ShortUrlApi
     }
 
     private function is_long($url) {
-        return strlen($url) >= 30;
+        return strlen($url) >= common_config('site', 'shorturllength');
     }
 
     protected function http_post($data) {
diff --git a/lib/common.php b/lib/common.php
index 01d2c78eaa..151b31d80a 100644
--- a/lib/common.php
+++ b/lib/common.php
@@ -89,6 +89,7 @@ $config =
               'private' => false,
               'ssl' => 'never',
               'sslserver' => null,
+              'shorturllength' => 30,
               'dupelimit' => 60), # default for same person saying the same thing
         'syslog' =>
         array('appname' => 'laconica', # for syslog