diff --git a/tests/lib/terminal.py b/tests/lib/terminal.py
index de181035..e5749d57 100644
--- a/tests/lib/terminal.py
+++ b/tests/lib/terminal.py
@@ -5,6 +5,7 @@ import threading
 
 from time import sleep
 from itertools import groupby
+from signal import SIGKILL
 
 import pexpect
 
@@ -24,6 +25,7 @@ class ExpectProcess(threading.Thread):
 		self.env = env
 		self.buffer = []
 		self.child_lock = threading.Lock()
+		self.shutdown_event = threading.Event()
 
 	def run(self):
 		child = pexpect.spawn(self.cmd, self.args, cwd=self.cwd, env=self.env)
@@ -32,7 +34,7 @@ class ExpectProcess(threading.Thread):
 		sleep(0.5)
 		self.child = child
 		status = None
-		while status is None:
+		while status is None and not self.shutdown_event.is_set():
 			try:
 				with self.child_lock:
 					s = child.read_nonblocking(size=1024, timeout=0)
@@ -46,6 +48,12 @@ class ExpectProcess(threading.Thread):
 					self.vterm.push(s)
 					self.buffer.append(s)
 
+		if status is None:
+			child.kill(SIGKILL)
+
+	def kill(self):
+		self.shutdown_event.set()
+
 	def resize(self, rows, cols):
 		with self.child_lock:
 			self.rows = rows
diff --git a/tests/test_in_vterm/test_tmux.py b/tests/test_in_vterm/test_tmux.py
index ad7ed791..b46ce89f 100755
--- a/tests/test_in_vterm/test_tmux.py
+++ b/tests/test_in_vterm/test_tmux.py
@@ -306,8 +306,9 @@ def main(attempts=3):
 		if ret is not None:
 			return ret
 	finally:
-		check_call([tmux_exe, '-S', socket_path, 'kill-server'], env=env,
-		           cwd=VTERM_TEST_DIR)
+		p.kill()
+		p.join(10)
+		assert(not p.isAlive())
 	return main(attempts=(attempts - 1))