diff --git a/tests/ci/tee_popen.py b/tests/ci/tee_popen.py
index ad3e62dab9c..53b0a0f6c2c 100644
--- a/tests/ci/tee_popen.py
+++ b/tests/ci/tee_popen.py
@@ -3,7 +3,6 @@
 import logging
 import os
 import signal
-import subprocess
 import sys
 from io import TextIOWrapper
 from pathlib import Path
@@ -34,7 +33,6 @@ class TeePopen:
         self.timeout_exceeded = False
         self.terminated_by_sigterm = False
         self.terminated_by_sigkill = False
-        self.pid = 0
 
     def _check_timeout(self) -> None:
         if self.timeout is None:
@@ -75,8 +73,7 @@ class TeePopen:
             errors="backslashreplace",
         )
         sleep(1)
-        self.pid = self._get_child_pid()
-        print(f"Subprocess started, pid [{self.process.pid}], child pid [{self.pid}]")
+        print(f"Subprocess started, pid [{self.process.pid}]")
         if self.timeout is not None and self.timeout > 0:
             t = Thread(target=self._check_timeout)
             t.daemon = True  # does not block the program from exit
@@ -97,22 +94,6 @@ class TeePopen:
 
         self.log_file.close()
 
-    def _get_child_pid(self):
-        # linux only
-        ps_command = f"ps --ppid {self.process.pid} -o pid="
-        res = "NA"
-        try:
-            result = subprocess.run(
-                ps_command, shell=True, capture_output=True, text=True
-            )
-            res = result.stdout.strip()
-            pid = int(res)
-            return pid
-        except Exception as e:
-            print(f"Failed to get child's pid, command [{ps_command}], result [{res}]")
-            print(f"ERROR: getting Python subprocess PID: {e}")
-            return self.process.pid
-
     def wait(self) -> int:
         if self.process.stdout is not None:
             for line in self.process.stdout:
@@ -125,10 +106,7 @@ class TeePopen:
         return self.process.poll()
 
     def send_signal(self, signal_num):
-        if self.pid:
-            os.kill(self.pid, signal_num)
-        else:
-            print("ERROR: no process to send signal")
+        os.killpg(self.process.pid, signal_num)
 
     @property
     def process(self) -> Popen: