diff --git a/src/Main.hs b/src/Main.hs
index 8092977..0945f6d 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -15,7 +15,7 @@ import Data.MIME.Charset (defaultCharsets)
 import Data.Text.Encoding (encodeUtf8)
 import Network.HostName (getHostName)
 import Network.Socket (SockAddr(SockAddrUnix))
-import Options.Applicative (Parser, ReadM, eitherReader, execParser, strOption, option, hsubparser, command, info, progDesc, long, short, metavar, value, showDefault, help, header, fullDesc, helper, (<**>))
+import Options.Applicative (Parser, ReadM, auto, eitherReader, execParser, strOption, option, hsubparser, command, info, progDesc, long, short, metavar, value, showDefault, help, header, fullDesc, helper, (<**>))
 import System.Directory (findExecutable)
 import System.Exit (exitWith)
 import System.Exit.Codes (codeTempFail)
@@ -32,12 +32,12 @@ import TiedoteMD.State
 import TiedoteMD.Types
 import TiedoteMD.Debug
 
-serverMain :: SockAddr -> Mailbox -> FilePath -> FilePath -> IO ()
-serverMain socket mail repoPath sendmailPath = do
+serverMain :: SockAddr -> Mailbox -> FilePath -> FilePath -> Int -> IO ()
+serverMain socket mail repoPath sendmailPath port = do
     acid <- openLocalState $ emptyState
     _ <- forkIO $ acidServerSockAddr skipAuthenticationCheck socket acid
     queueMessages acid
-    _ <- forkIO $ scotty 3000 $ do
+    _ <- forkIO $ scotty port $ do
         defaultHandler $ liftAndCatchIO . LT.putStrLn -- Don't return exceptions to clients
         post "/" $ liftAndCatchIO $ void $ forkIO $ updateMessages acid repoPath
     updateMessages acid repoPath
@@ -59,7 +59,7 @@ printStateMain socket = do
     printState acid
 
 data Config = Config { socketPath :: FilePath, mail :: Mailbox, sendmailCommand :: String, runMode :: RunMode } deriving Show
-data RunMode = Server { repoPath :: FilePath } | Recieve | Print deriving Show
+data RunMode = Server { repoPath :: FilePath, portNumber :: Int } | Recieve | Print deriving Show
 
 config :: Maybe Mailbox -> Parser Config
 config mail = Config
@@ -71,7 +71,9 @@ config mail = Config
         <> command "state" (info (pure Print) (progDesc "Print the server's current state")))
 
 serverCommand :: Parser RunMode
-serverCommand = Server <$> strOption (long "repository" <> short 'r' <> metavar "DIRECTORY" <> value "/var/lib/tiedote.md/git-repo" <> showDefault <> help "Path to git repository")
+serverCommand = Server
+    <$> strOption (long "repository" <> short 'r' <> metavar "DIRECTORY" <> value "/var/lib/tiedote.md/git-repo" <> showDefault <> help "Path to git repository")
+    <*> option auto (long "port" <> short 'p' <> metavar "PORT" <> value 3000 <> showDefault <> help "TCP port number to listen on for webhook notifications")
 
 readMailbox :: ReadM Mailbox
 readMailbox = eitherReader $ parse (mailbox defaultCharsets) . encodeUtf8 . T.pack
@@ -88,4 +90,4 @@ main = do
     case args of
       Config {runMode = Recieve, ..} -> clientMain (SockAddrUnix socketPath) mail sendmailPath
       Config {runMode = Print, ..} -> printStateMain (SockAddrUnix socketPath)
-      Config {runMode = Server {..}, ..} -> serverMain (SockAddrUnix socketPath) mail repoPath sendmailPath
+      Config {runMode = Server {..}, ..} -> serverMain (SockAddrUnix socketPath) mail repoPath sendmailPath portNumber