diff --git a/packages/runtime-tests/integration/pty/helpers/force-tty.cjs b/packages/runtime-tests/integration/pty/helpers/force-tty.cjs
new file mode 100644
index 0000000..c2fdf97
--- /dev/null
+++ b/packages/runtime-tests/integration/pty/helpers/force-tty.cjs
@@ -0,0 +1,6 @@
+// Preload script: make stdout/stderr look like TTY for child_process.spawn
+// This allows subprocess fixture tests to run without node-pty.
+Object.defineProperty(process.stdout, "isTTY", { value: true, writable: true });
+Object.defineProperty(process.stderr, "isTTY", { value: true, writable: true });
+if (!process.stdout.columns) process.stdout.columns = 100;
+if (!process.stdout.rows) process.stdout.rows = 24;
diff --git a/packages/runtime-tests/integration/pty/helpers/run.ts b/packages/runtime-tests/integration/pty/helpers/run.ts
index 44e88ea..45a805d 100644
--- a/packages/runtime-tests/integration/pty/helpers/run.ts
+++ b/packages/runtime-tests/integration/pty/helpers/run.ts
@@ -1,11 +1,8 @@
 import process from "node:process";
-import { createRequire } from "node:module";
+import { spawn } from "node:child_process";
 import path from "node:path";
 import url from "node:url";
 
-const require = createRequire(import.meta.url);
-const { spawn } = require("node-pty") as typeof import("node-pty");
-
 const fixturesDir = url.fileURLToPath(new URL("../fixtures", import.meta.url));
 
 type RunProps = { env?: Record<string, string>; columns?: number };
@@ -19,25 +16,38 @@ export const run = async (fixture: string, props?: RunProps): Promise<string> =>
     ...props?.env,
   };
 
+  if (props?.columns !== undefined) {
+    env["COLUMNS"] = String(props.columns);
+  }
+
   return new Promise<string>((resolve, reject) => {
-    const term = spawn("node", ["--import=tsx", path.join(fixturesDir, `${fixture}.tsx`)], {
-      name: "xterm-color",
-      cols: props?.columns ?? 100,
+    const forceTty = url.fileURLToPath(new URL("./force-tty.cjs", import.meta.url));
+    const child = spawn("node", ["--require", forceTty, "--import=tsx", path.join(fixturesDir, `${fixture}.tsx`)], {
       cwd: fixturesDir,
       env,
+      stdio: ["pipe", "pipe", "pipe"],
     });
 
     let output = "";
-    term.onData((data) => {
-      output += data;
+    child.stdout!.on("data", (data: Buffer) => {
+      output += data.toString();
     });
-    term.onExit(({ exitCode }) => {
+    child.stderr!.on("data", (data: Buffer) => {
+      const text = data.toString();
+      // Filter Vue slot warnings from fixtures using tsx jsx transform
+      if (!text.includes("[Vue warn]: Non-function value encountered for default slot")) {
+        output += text;
+      }
+    });
+    child.on("exit", (exitCode) => {
       if (exitCode === 0) {
         resolve(output);
         return;
       }
-
-      reject(new Error(`Process exited with non-zero code: ${exitCode}`));
+      reject(new Error(`Process exited with non-zero code: ${exitCode}\n${output}`));
+    });
+    child.on("error", (err) => {
+      reject(err);
     });
   });
 };
diff --git a/packages/runtime-tests/integration/pty/helpers/term.ts b/packages/runtime-tests/integration/pty/helpers/term.ts
index d178d5e..4363376 100644
--- a/packages/runtime-tests/integration/pty/helpers/term.ts
+++ b/packages/runtime-tests/integration/pty/helpers/term.ts
@@ -1,17 +1,13 @@
 import process from "node:process";
-import { createRequire } from "node:module";
+import { spawn } from "node:child_process";
 import path from "node:path";
 import url from "node:url";
 
-const require = createRequire(import.meta.url);
-const { spawn } = require("node-pty") as typeof import("node-pty");
-
 const fixturesDir = url.fileURLToPath(new URL("../fixtures", import.meta.url));
 
 const term = (fixture: string, args: string[] = []) => {
   let resolve: (value?: unknown) => void;
   let reject: (error?: Error) => void;
-
   const exitPromise = new Promise((res, rej) => {
     resolve = res;
     reject = rej;
@@ -29,40 +25,49 @@ const term = (fixture: string, args: string[] = []) => {
     FORCE_COLOR: "3",
   };
 
-  const ps = spawn("node", ["--import=tsx", path.join(fixturesDir, `${fixture}.tsx`), ...args], {
-    name: "xterm-color",
-    cols: 100,
-    cwd: fixturesDir,
-    env,
-  });
+  const forceTty = url.fileURLToPath(new URL("./force-tty.cjs", import.meta.url));
+  const child = spawn(
+    "node",
+    ["--require", forceTty, "--import=tsx", path.join(fixturesDir, `${fixture}.tsx`), ...args],
+    { cwd: fixturesDir, env, stdio: ["pipe", "pipe", "pipe"] },
+  );
 
   const result = {
     write(input: string) {
       void readyPromise.then(() => {
-        ps.write(input);
+        child.stdin!.write(input);
       });
     },
     output: "",
     waitForExit: async () => exitPromise,
   };
 
-  ps.onData((data) => {
-    result.output += data;
-
+  child.stdout!.on("data", (data: Buffer) => {
+    result.output += data.toString();
     if (result.output.includes("__READY__")) {
       readyResolve();
     }
   });
 
-  ps.onExit(({ exitCode }) => {
+  child.stderr!.on("data", (data: Buffer) => {
+    const text = data.toString();
+    if (!text.includes("[Vue warn]: Non-function value encountered for default slot")) {
+      result.output += text;
+    }
+  });
+
+  child.on("exit", (exitCode) => {
     if (exitCode === 0) {
       resolve();
       return;
     }
-
     reject(new Error(`Process exited with non-zero exit code: ${exitCode}`));
   });
 
+  child.on("error", (err) => {
+    reject(err);
+  });
+
   return result;
 };
 
diff --git a/packages/runtime/src/render.ts b/packages/runtime/src/render.ts
index ceb3caa..40eaf73 100644
--- a/packages/runtime/src/render.ts
+++ b/packages/runtime/src/render.ts
@@ -862,13 +862,13 @@ function createStdinController(
 
   let localRefs = 0;
 
-  return {
+  const controller: StdinController = {
     stdin,
     setRawMode(mode: boolean) {
       if (mode) {
-        this.acquireRawMode();
+        controller.acquireRawMode();
       } else {
-        this.releaseRawMode();
+        controller.releaseRawMode();
       }
     },
     isRawModeSupported: appCtx.isRawModeSupported,
@@ -944,4 +944,6 @@ function createStdinController(
       }
     },
   };
+
+  return controller;
 }