diff --git a/Network/Wai/Handler/Launch.hs b/Network/Wai/Handler/Launch.hs
--- a/Network/Wai/Handler/Launch.hs
+++ b/Network/Wai/Handler/Launch.hs
@@ -124,7 +124,7 @@
 #else
     "xdg-open"
 #endif
-    ["http://localhost:4587/"] >> return ()) >> return ()
+    ["http://127.0.0.1:4587/"] >> return ()) >> return ()
 #endif
 
 run :: Application -> IO ()
@@ -133,6 +133,7 @@
     forkIO $ Warp.runSettings Warp.defaultSettings
         { Warp.settingsPort = 4587
         , Warp.settingsOnException = const $ return ()
+        , Warp.settingsHost = "127.0.0.1"
         } $ ping x app
     launch
     loop x
diff --git a/wai-handler-launch.cabal b/wai-handler-launch.cabal
--- a/wai-handler-launch.cabal
+++ b/wai-handler-launch.cabal
@@ -1,5 +1,5 @@
 Name:                wai-handler-launch
-Version:             0.0.0
+Version:             0.0.1
 Synopsis:            Launch a web app in the default browser.
 Description:         This handles cross-platform launching and inserts Javascript code to ping the server. When the server no longer receives pings, it shuts down.
 License:             BSD3
diff --git a/windows.c b/windows.c
--- a/windows.c
+++ b/windows.c
@@ -3,5 +3,5 @@
 
 void launch(void)
 {
-    ShellExecute(NULL, "open", "http://localhost:4587/", NULL, NULL, SW_SHOWNORMAL);
+    ShellExecute(NULL, "open", "http://127.0.0.1:4587/", NULL, NULL, SW_SHOWNORMAL);
 }