diff --git a/src/pages/index.tsx b/src/pages/index.tsx
index 542679d..e74d999 100644
--- a/src/pages/index.tsx
+++ b/src/pages/index.tsx
@@ -118,7 +118,7 @@ export default () => (
           <State status={app.state}>{stateLabels[app.state]}</State>
         </AppHeader>
 
-        {app.port && <Info>Port: {app.port}</Info>}
+        {app.port ? <Info>Port: {app.port}</Info> : null}
         {app.started && <Info>Started: {new Date(app.started).toLocaleString()}</Info>}
 
         <ActionBar>
diff --git a/src/server/apps.ts b/src/server/apps.ts
index e5de418..397f519 100644
--- a/src/server/apps.ts
+++ b/src/server/apps.ts
@@ -137,6 +137,7 @@ const runApp = async (dir: string, port: number) => {
     // Reset to stopped state (or invalid if no longer valid)
     app.state = isApp(dir) ? 'stopped' : 'invalid'
     app.proc = undefined
+    app.port = undefined
     app.started = undefined
   })
 }