diff --git a/Main.hs b/Main.hs
--- a/Main.hs
+++ b/Main.hs
@@ -1,30 +1,54 @@
-{-# LANGUAGE OverloadedStrings, DeriveDataTypeable #-}
+{-# LANGUAGE OverloadedStrings, DeriveDataTypeable, ExistentialQuantification #-}
 
+import Paths_latest_npm_version (version)
+import Control.Exception (fromException, Exception, SomeException)
+import Network.HTTP.Client (HttpException(StatusCodeException))
+import Network.HTTP.Types.Status (statusCode)
 import Data.Data (Data)
+import Data.Version (showVersion)
 import Data.Typeable (Typeable)
-import Npm.Latest (fetchLatestVersion)
+import Npm.Latest (fetchLatestVersion, GenericNpmException(..))
 import System.Console.CmdArgs.Implicit (cmdArgsRun, (&=))
+import System.Console.CmdArgs.Explicit (HelpFormat(..), helpText)
+import System.IO (stderr)
 
 import qualified Data.Text as T
 import qualified Data.Text.IO as TIO
 import qualified System.Console.CmdArgs.Implicit as CA
 
 
+data ErrHandler a = forall e . Exception e => ErrHandler (e -> a)
+
+matchErr :: SomeException -> b -> [ErrHandler b] -> b
+matchErr e = foldr (\(ErrHandler f) r -> maybe r f $ fromException e)
+
 data LatestNpmVersion = LatestNpmVersion {name :: String}
     deriving (Show, Data, Typeable)
 
+programName :: String
+programName = "latest-npm-version"
+
 args :: CA.Mode (CA.CmdArgs LatestNpmVersion)
 args = CA.cmdArgsMode $ LatestNpmVersion{name = CA.def &= CA.args}
-       &= CA.summary "latest-npm-version v0.1.0"
+       &= CA.summary (unwords [programName, showVersion version])
+       &= CA.program programName
 
 main :: IO ()
 main = do
     mainArgs <- cmdArgsRun args
-    let moduleName = (name mainArgs)
-    if length moduleName == 0
-        then TIO.putStrLn "Missing module name. Consult --help."
-        else do
-            version <- fetchLatestVersion moduleName
-            case version of
-                Nothing -> TIO.putStrLn "Error: fetching/parsing JSON failed"
-                Just v -> TIO.putStrLn $ T.unwords [T.pack moduleName, v]
+    let moduleName = name mainArgs
+    if null moduleName
+        then print $ helpText [] HelpFormatDefault args
+        else fetchLatestVersion moduleName >>= either handleErr TIO.putStrLn
+
+handleErr :: SomeException -> IO ()
+handleErr err = TIO.hPutStrLn stderr $ matchErr err handleOther
+    [ErrHandler handleA, ErrHandler handleB] where
+        handleA GenericNpmException = "Invalid JSON data received."
+        handleB (StatusCodeException status _ _) =
+            if statusCode status == 404
+                then "Package not found."
+                else T.unwords
+                    ["Invalid status code ", T.pack $ show $ statusCode status]
+        handleB s@_ = T.unwords ["HTTP error: ", T.pack $ show s]
+        handleOther = "Unknown error."
diff --git a/Npm/Latest.hs b/Npm/Latest.hs
--- a/Npm/Latest.hs
+++ b/Npm/Latest.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-|
-Module      : Npm.Latestj
+Module      : Npm.Latest
 Description : Fetch the latest version of an npm module.
 Copyright   : (c) Pascal Hartig, 2014
 License     : MIT
@@ -13,18 +13,20 @@
 -}
 module Npm.Latest (
     fetchLatestVersion,
-    extractVersion
+    extractVersion,
+    GenericNpmException(..)
 ) where
 
-import Npm.Latest.Internal (buildRequest, makeVersionRequest, extractVersion)
+import Control.Exception (SomeException)
 import Data.Text.Format (Format)
+import Npm.Latest.Internal (buildRequest, makeVersionRequest, extractVersion, GenericNpmException(..))
 import qualified Data.Text as T
 
 latestUrl :: Format
 latestUrl = "https://registry.npmjs.org/{}/latest"
 
 -- |Fetch the latest version for the given module name.
-fetchLatestVersion :: String -> IO (Maybe T.Text)
+fetchLatestVersion :: String -> IO (Either SomeException T.Text)
 fetchLatestVersion name = do
     req <- buildRequest name latestUrl
     resp <- makeVersionRequest req
diff --git a/Tests/Main.hs b/Tests/Main.hs
--- a/Tests/Main.hs
+++ b/Tests/Main.hs
@@ -2,21 +2,28 @@
 module Main where
 
 import Test.Hspec
-import Npm.Latest (extractVersion)
+import Control.Exception (SomeException(..), toException)
+import Npm.Latest (extractVersion, GenericNpmException(..))
 
 import qualified Data.Text as T
 
+instance Eq SomeException where
+    -- Terrible hack, but this is for tests, so it's fine, right?
+    a == b = show a == show b
+
 main :: IO ()
 main = hspec $ do
     describe "extractVersion" $ do
-        it "returns Just for a valid JSON object" $ do
+        it "is Right for a valid JSON object" $ do
             let json = T.unpack "{\"version\": \"1.0\"}"
-            extractVersion (Just $ Right $ json) `shouldBe` Just "1.0"
+            extractVersion (Right json) `shouldBe` (Right "1.0")
 
-        it "returns Nothing for a malformed JSON object" $ do
+        it "is Left for a malformed JSON object" $ do
             let json = T.unpack "{\"description\": \"not what we expect\"}"
-            extractVersion (Just $ Right $ json) `shouldBe` Nothing
+            extractVersion (Right $ json) `shouldBe`
+                (Left $ toException GenericNpmException)
 
-        it "returns Nothing for a malformed JSON object" $ do
+        it "is Left for a malformed JSON object" $ do
             let json = T.unpack "not even $ JSON"
-            extractVersion (Just $ Right $ json) `shouldBe` Nothing
+            extractVersion (Right $ json) `shouldBe`
+                (Left $ toException GenericNpmException)
diff --git a/latest-npm-version.cabal b/latest-npm-version.cabal
--- a/latest-npm-version.cabal
+++ b/latest-npm-version.cabal
@@ -1,5 +1,5 @@
 name:                  latest-npm-version
-version:               0.2.1
+version:               0.3.0
 synopsis:              Find the latest version of a package on npm
 homepage:              https://github.com/passy/latest-npm-version
 license:               MIT
@@ -29,7 +29,9 @@
                        aeson >= 0.7 && < 0.8,
                        pipes-attoparsec >= 0.5 && < 0.6,
                        transformers >= 0.3 && < 0.4,
-                       lens >= 4.1 && < 4.2
+                       lens >= 4.1 && < 4.2,
+                       http-client >= 0.3 && < 0.4,
+                       http-types == 0.8.*
   default-language:    Haskell2010
 
 executable latest-npm-version
@@ -47,7 +49,9 @@
                        pipes-attoparsec >= 0.5 && < 0.6,
                        transformers >= 0.3 && < 0.4,
                        lens >= 4.1 && < 4.2,
-                       cmdargs >= 0.10 && < 0.11
+                       cmdargs >= 0.10 && < 0.11,
+                       http-client >= 0.3 && < 0.4,
+                       http-types == 0.8.*
   default-language:    Haskell2010
 
 
@@ -65,4 +69,6 @@
                   aeson >= 0.7 && < 0.8,
                   pipes-attoparsec >= 0.5 && < 0.6,
                   transformers >= 0.3 && < 0.4,
-                  lens >= 4.1 && < 4.2
+                  lens >= 4.1 && < 4.2,
+                  http-client >= 0.3 && < 0.4,
+                  http-types == 0.8.*