diff --git a/pyproject.toml b/pyproject.toml
index 5dacd4a..dc4b598 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,7 +37,13 @@ requires = ["hatchling"]
 build-backend = "hatchling.build"
 
 [dependency-groups]
-dev = ["prek>=0.2", "pyte>=0.8", "pytest>=8.0", "ty>=0.0.89"]
+dev = [
+    "prek>=0.2",
+    "pyte>=0.8",
+    "pytest>=8.0",
+    "pytest-xdist>=3.0",
+    "ty>=0.0.89",
+]
 
 [tool.ty.src]
 # Only the package and its tests; agent worktrees under .claude/ would
@@ -53,6 +59,10 @@ select = ["E", "F", "W", "I", "UP"]
 [tool.ruff.lint.isort]
 known-first-party = ["pqcli"]
 
+[tool.pytest.ini_options]
+# Run tests in parallel; pass -n0 to run them one by one.
+addopts = "-n auto"
+
 [tool.coverage.run]
 # Also measure the pqcli processes the tests start, such as the curses
 # UI driven through a pseudo-terminal.
diff --git a/tests/pty_app.py b/tests/pty_app.py
index 5766c92..1fbe42c 100644
--- a/tests/pty_app.py
+++ b/tests/pty_app.py
@@ -1,14 +1,14 @@
 """Run pqcli in a pseudo-terminal and read its screen through pyte.
 
-Only works on POSIX: it needs pty.fork and the termios ioctls.
+Only works on POSIX: it needs a pty and the termios ioctls.
 """
 
 import fcntl
 import os
-import pty
 import select
 import signal
 import struct
+import subprocess
 import sys
 import termios
 import time
@@ -75,18 +75,33 @@ class PtyApp:
         # LINES/COLUMNS would override the pty size seen by curses.
         env.pop("LINES", None)
         env.pop("COLUMNS", None)
-        argv = [sys.executable, "-m", "pqcli", *args]
+        # The child makes the pty its controlling terminal, so that ^C
+        # raises SIGINT as in a real terminal, then becomes pqcli.
+        argv = [
+            sys.executable,
+            "-c",
+            "import fcntl, sys, termios, runpy; "
+            "fcntl.ioctl(0, termios.TIOCSCTTY, 0); "
+            "sys.argv[0] = 'pqcli'; "
+            "runpy.run_module('pqcli', run_name='__main__')",
+            *args,
+        ]
 
-        pid, fd = pty.fork()
-        if pid == 0:  # pragma: no cover - runs in the child
-            try:
-                _set_size(0, rows, cols)
-                if cwd is not None:
-                    os.chdir(cwd)
-                os.execve(sys.executable, argv, env)
-            finally:
-                os._exit(127)
-        self.pid = pid
+        # Popen forks and execs in C, which is safe in the threaded
+        # pytest-xdist workers, unlike pty.fork().
+        fd, child_fd = os.openpty()
+        _set_size(child_fd, rows, cols)
+        self._process = subprocess.Popen(
+            argv,
+            stdin=child_fd,
+            stdout=child_fd,
+            stderr=child_fd,
+            env=env,
+            cwd=cwd,
+            start_new_session=True,
+        )
+        os.close(child_fd)
+        self.pid = self._process.pid
         self.fd = fd
 
     # reading ---------------------------------------------------------
@@ -202,9 +217,9 @@ class PtyApp:
         while self.exit_status is None:
             # keep draining so the child never blocks on a full pty
             self._pump(0.02)
-            pid, status = os.waitpid(self.pid, os.WNOHANG)
-            if pid:
-                self.exit_status = os.waitstatus_to_exitcode(status)
+            status = self._process.poll()
+            if status is not None:
+                self.exit_status = status
                 break
             if time.monotonic() > deadline:
                 raise AssertionError(
diff --git a/uv.lock b/uv.lock
index 37545c7..d700264 100644
--- a/uv.lock
+++ b/uv.lock
@@ -23,6 +23,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/8a/0e/97c33bf5009bdbac74fd2beace167cab3f978feb69cc36f1ef79360d6c4e/exceptiongroup-1.3.1-py3-none-any.whl", hash = "sha256:a7a39a3bd276781e98394987d3a5701d0c4edffb633bb7a5144577f82c773598", size = 16740, upload-time = "2025-11-21T23:01:53.443Z" },
 ]
 
+[[package]]
+name = "execnet"
+version = "2.1.2"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/bf/89/780e11f9588d9e7128a3f87788354c7946a9cbb1401ad38a48c4db9a4f07/execnet-2.1.2.tar.gz", hash = "sha256:63d83bfdd9a23e35b9c6a3261412324f964c2ec8dcd8d3c6916ee9373e0befcd", size = 166622, upload-time = "2025-11-12T09:56:37.75Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/ab/84/02fc1827e8cdded4aa65baef11296a9bbe595c474f0d6d758af082d849fd/execnet-2.1.2-py3-none-any.whl", hash = "sha256:67fba928dd5a544b783f6056f449e5e3931a5c378b128bc18501f7ea79e296ec", size = 40708, upload-time = "2025-11-12T09:56:36.333Z" },
+]
+
 [[package]]
 name = "iniconfig"
 version = "2.3.1"
@@ -68,6 +77,7 @@ dev = [
     { name = "prek" },
     { name = "pyte" },
     { name = "pytest" },
+    { name = "pytest-xdist" },
     { name = "ty" },
 ]
 
@@ -83,6 +93,7 @@ dev = [
     { name = "prek", specifier = ">=0.2" },
     { name = "pyte", specifier = ">=0.8" },
     { name = "pytest", specifier = ">=8.0" },
+    { name = "pytest-xdist", specifier = ">=3.0" },
     { name = "ty", specifier = ">=0.0.89" },
 ]
 
@@ -142,6 +153,19 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/24/25/1de2678b631f5a49215c6c96fff41ba892b0a34df68d6d80292b1b48aa7f/pytest-9.1.1-py3-none-any.whl", hash = "sha256:37a86b45efb9a47a61a36449063e8e18d0cab3161329fc099eb21783169c4f0c", size = 386536, upload-time = "2026-06-19T10:58:31.347Z" },
 ]
 
+[[package]]
+name = "pytest-xdist"
+version = "3.8.0"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "execnet" },
+    { name = "pytest" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/78/b4/439b179d1ff526791eb921115fca8e44e596a13efeda518b9d845a619450/pytest_xdist-3.8.0.tar.gz", hash = "sha256:7e578125ec9bc6050861aa93f2d59f1d8d085595d6551c2c90b6f4fad8d3a9f1", size = 88069, upload-time = "2025-07-01T13:30:59.346Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/ca/31/d4e37e9e550c2b92a9cbc2e4d0b7420a27224968580b5a447f420847c975/pytest_xdist-3.8.0-py3-none-any.whl", hash = "sha256:202ca578cfeb7370784a8c33d6d05bc6e13b4f25b5053c30a152269fd10f0b88", size = 46396, upload-time = "2025-07-01T13:30:56.632Z" },
+]
+
 [[package]]
 name = "tomli"
 version = "2.5.0"