diff --git a/sdk/packages/core/src/hub/daemon/index.test.ts b/sdk/packages/core/src/hub/daemon/index.test.ts
index e599b4ea7f..d1e77ab572 100644
--- a/sdk/packages/core/src/hub/daemon/index.test.ts
+++ b/sdk/packages/core/src/hub/daemon/index.test.ts
@@ -101,16 +101,21 @@ describe("ensureDetachedHubServer", () => {
 		}
 	});
 
-	it("starts the daemon on the resolved default hub port", async () => {
+	it("lets the daemon bind port 0 when the default endpoint is occupied", async () => {
 		readHubDiscovery.mockResolvedValueOnce(undefined).mockResolvedValueOnce({
-			url: "ws://127.0.0.1:25463/hub",
+			url: "ws://127.0.0.1:5555/hub",
 			buildId: "current-build",
 			authToken: "new-token",
 		});
-		probeHubServer.mockResolvedValueOnce(undefined).mockResolvedValueOnce({
-			url: "ws://127.0.0.1:25463/hub",
-			buildId: "current-build",
-		});
+		probeHubServer
+			.mockResolvedValueOnce({
+				url: "ws://127.0.0.1:25463/hub",
+				buildId: "current-build",
+			})
+			.mockResolvedValueOnce({
+				url: "ws://127.0.0.1:5555/hub",
+				buildId: "current-build",
+			});
 		verifyHubConnection.mockResolvedValueOnce(true);
 
 		const { ensureDetachedHubServer } = await import(".");
@@ -123,15 +128,42 @@ describe("ensureDetachedHubServer", () => {
 			| undefined;
 
 		expect(result).toEqual({
-			url: "ws://127.0.0.1:25463/hub",
+			url: "ws://127.0.0.1:5555/hub",
 			authToken: "new-token",
 		});
 		expect(spawn).toHaveBeenCalledOnce();
 		expect(spawnArgs).toContain("--port");
-		expect(spawnArgs).toContain("25463");
+		expect(spawnArgs).toContain("0");
 		expect(spawnOptions?.env?.[CLINE_RUN_AS_HUB_DAEMON_ENV]).toBe("1");
 	});
 
+	it("keeps an explicit detached hub port fixed", async () => {
+		readHubDiscovery.mockResolvedValueOnce(undefined).mockResolvedValueOnce({
+			url: "ws://127.0.0.1:31000/hub",
+			buildId: "current-build",
+			authToken: "new-token",
+		});
+		probeHubServer.mockResolvedValueOnce(undefined).mockResolvedValueOnce({
+			url: "ws://127.0.0.1:31000/hub",
+			buildId: "current-build",
+		});
+		verifyHubConnection.mockResolvedValueOnce(true);
+
+		const { ensureDetachedHubServer } = await import(".");
+		const result = await ensureDetachedHubServer("/workspace", { port: 31000 });
+		const spawnCalls = (spawn as unknown as { mock: { calls: unknown[][] } })
+			.mock.calls;
+		const spawnArgs = spawnCalls[0]?.[1] as string[] | undefined;
+
+		expect(result).toEqual({
+			url: "ws://127.0.0.1:31000/hub",
+			authToken: "new-token",
+		});
+		expect(spawn).toHaveBeenCalledOnce();
+		expect(spawnArgs).toContain("--port");
+		expect(spawnArgs).toContain("31000");
+	});
+
 	it("retries a transient ETXTBSY spawn failure while starting the detached daemon", async () => {
 		vi.useFakeTimers();
 		try {
diff --git a/sdk/packages/core/src/hub/daemon/index.ts b/sdk/packages/core/src/hub/daemon/index.ts
index 8cae9e7822..456e6d6167 100644
--- a/sdk/packages/core/src/hub/daemon/index.ts
+++ b/sdk/packages/core/src/hub/daemon/index.ts
@@ -206,6 +206,8 @@ export function prewarmDetachedHubServer(
 		return;
 	}
 	const owner = resolveSharedHubOwnerContext();
+	const hasExplicitPort =
+		endpoint.port !== undefined || !!process.env.CLINE_HUB_PORT?.trim();
 	const resolvedEndpoint = resolveHubEndpointOptions(endpoint);
 	const expectedUrl = createHubServerUrl(
 		resolvedEndpoint.host,
@@ -238,7 +240,12 @@ export function prewarmDetachedHubServer(
 			if (expected?.url) {
 				await retireIncompatibleHub(expected, owner.discoveryPath);
 			}
-			await spawnDetachedHubServerWithRetry(workspaceRoot, resolvedEndpoint);
+			const shouldUseFallbackPort =
+				!hasExplicitPort && resolvedEndpoint.port !== 0;
+			const spawnEndpoint = shouldUseFallbackPort
+				? { ...resolvedEndpoint, port: 0 }
+				: resolvedEndpoint;
+			await spawnDetachedHubServerWithRetry(workspaceRoot, spawnEndpoint);
 		})
 		.catch(() => {
 			// best-effort prewarm only
@@ -260,6 +267,9 @@ export async function ensureDetachedHubServer(
 		endpointOverrides.port !== undefined ||
 		endpointOverrides.pathname !== undefined ||
 		!!process.env.CLINE_HUB_PORT?.trim();
+	const hasExplicitPort =
+		endpointOverrides.port !== undefined ||
+		!!process.env.CLINE_HUB_PORT?.trim();
 	const endpoint = resolveHubEndpointOptions(endpointOverrides);
 	const expectedUrl = createHubServerUrl(
 		endpoint.host,
@@ -302,7 +312,11 @@ export async function ensureDetachedHubServer(
 	if (expected?.url) {
 		await retireIncompatibleHub(expected, owner.discoveryPath);
 	}
-	await spawnDetachedHubServerWithRetry(workspaceRoot, endpoint);
+	const shouldUseFallbackPort = !hasExplicitPort && endpoint.port !== 0;
+	const spawnEndpoint = shouldUseFallbackPort
+		? { ...endpoint, port: 0 }
+		: endpoint;
+	await spawnDetachedHubServerWithRetry(workspaceRoot, spawnEndpoint);
 	const deadline = Date.now() + HUB_STARTUP_TIMEOUT_MS;
 	while (Date.now() < deadline) {
 		const nextDiscovery = await readHubDiscovery(owner.discoveryPath);