diff --git a/packages/opencode/src/server/server.ts b/packages/opencode/src/server/server.ts
index 3a480228e..69bd5e3be 100644
--- a/packages/opencode/src/server/server.ts
+++ b/packages/opencode/src/server/server.ts
@@ -53,6 +53,9 @@ globalThis.AI_SDK_LOG_WARNINGS = false
 export namespace Server {
   const log = Log.create({ service: "server" })
 
+  // Port that the server is running on, used to inject into frontend HTML
+  let serverPort: number = 4096
+
   export const Event = {
     Connected: BusEvent.define("server.connected", z.object({})),
     Disposed: BusEvent.define("global.disposed", z.object({})),
@@ -2613,24 +2616,15 @@ export namespace Server {
     return result
   }
 
-  let serverPort: number = 4096
-
   export function listen(opts: { port: number; hostname: string }) {
     const args = {
       hostname: opts.hostname,
       idleTimeout: 0,
       fetch: App().fetch,
       websocket: websocket,
-    } as const
-    if (opts.port === 0) {
-      try {
-        serverPort = 4096
-        return Bun.serve({ ...args, port: 4096 })
-      } catch {
-        // port 4096 not available, fall through to use port 0
-      }
-    }
-    serverPort = opts.port
-    return Bun.serve({ ...args, port: opts.port })
+    })
+    // Store the actual port for injection into frontend HTML
+    serverPort = server.port ?? opts.port
+    return server
   }
 }