diff --git a/package.json b/package.json
index 485e2640..a8c03220 100644
--- a/package.json
+++ b/package.json
@@ -62,8 +62,8 @@
     "import-history": "node scripts/import-history.js",
     "reconcile-tokens": "node scripts/import-history.js --reconcile-tokens",
     "clear-data": "node scripts/clear-data.js",
-    "test": "node --test server/__tests__/*.test.js && cd client && npm test",
-    "test:server": "node --test server/__tests__/*.test.js",
+    "test": "node scripts/test-server.js && cd client && npm test",
+    "test:server": "node scripts/test-server.js",
     "test:client": "cd client && npm test",
     "format": "prettier --write .",
     "format:check": "prettier --check .",
diff --git a/scripts/test-server.js b/scripts/test-server.js
new file mode 100644
index 00000000..6496c97d
--- /dev/null
+++ b/scripts/test-server.js
@@ -0,0 +1,42 @@
+#!/usr/bin/env node
+/**
+ * @file test-server.js
+ * @description Runs the server test suite against a PRIVATE tmux server.
+ * Several suites start real `agenthub-lane-<id>` tmux sessions and then kill
+ * or reset them, with lane ids from their own throwaway database — on the
+ * user's default tmux server those names collide with the dashboard's real
+ * lane panes, and a test run kills whichever live session shares an id
+ * (including the pane the test was launched from). Dropping `TMUX` and
+ * pointing `TMUX_TMPDIR` at a fresh directory gives every tmux call — the
+ * app's own and the tests' direct `execFileSync("tmux", …)` — its own socket.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+const { spawnSync } = require("node:child_process");
+const fs = require("node:fs");
+const os = require("node:os");
+const path = require("node:path");
+
+const root = path.join(__dirname, "..");
+const dir = path.join(root, "server", "__tests__");
+const files = fs
+  .readdirSync(dir)
+  .filter((f) => f.endsWith(".test.js"))
+  .map((f) => path.join(dir, f));
+const args = process.argv.slice(2);
+
+const tmuxDir = fs.mkdtempSync(path.join(os.tmpdir(), "agenthub-test-tmux-"));
+const env = { ...process.env, TMUX_TMPDIR: tmuxDir };
+delete env.TMUX;
+delete env.TMUX_PANE;
+
+const result = spawnSync(process.execPath, ["--test", ...args, ...(args.length ? [] : files)], {
+  stdio: "inherit",
+  env,
+  cwd: root,
+});
+
+// Whatever a test leaked dies with the private server, never a real pane.
+spawnSync("tmux", ["kill-server"], { env, stdio: "ignore" });
+fs.rmSync(tmuxDir, { recursive: true, force: true });
+process.exit(result.status ?? 1);
diff --git a/server/__tests__/lane-lifecycle.test.js b/server/__tests__/lane-lifecycle.test.js
index dc6996e9..d36c65ba 100644
--- a/server/__tests__/lane-lifecycle.test.js
+++ b/server/__tests__/lane-lifecycle.test.js
@@ -848,17 +848,12 @@ describe("destructive lane lifecycle actions", () => {
     const runId = started.body.lane.run_id;
 
     // Mock tmux so has-session always returns 0 (session exists), simulating a stuck session
-    tmux.__setExecImpl(async (cmd, args) => {
-      if (cmd === "tmux" && args[0] === "has-session" && args[1] === "-t" && args[2] === runId) {
-        return { code: 0, stdout: "", stderr: "" };
-      }
-      if (cmd === "tmux" && args[0] === "list-sessions") {
-        return { code: 0, stdout: "", stderr: "" };
-      }
-      if (cmd === "tmux" && args[0] === "kill-session" && args[1] === "-t" && args[2] === runId) {
-        return { code: 0, stdout: "", stderr: "" };
-      }
-      return { code: 1, stdout: "", stderr: "" };
+    // Same shape as tmux.js's own exec: sync, argv only, throws on failure.
+    tmux.__setExecImpl((args) => {
+      if (args[0] === "has-session" && args[2] === runId) return "";
+      if (args[0] === "list-sessions") return `${runId}\n`;
+      if (args[0] === "kill-session" && args[2] === runId) return "";
+      throw Object.assign(new Error("mocked tmux failure"), { status: 1 });
     });
 
     try {