diff --git a/scripts/tests/chiptest/runner.py b/scripts/tests/chiptest/runner.py
index 03af6af0e32c22..56660c0b5258be 100644
--- a/scripts/tests/chiptest/runner.py
+++ b/scripts/tests/chiptest/runner.py
@@ -13,17 +13,14 @@
 # limitations under the License.
 
 import logging
-import os
-import pty
 import re
 import subprocess
-import sys
 import threading
 
 
 class LogPipe(threading.Thread):
 
-    def __init__(self, level, capture_delegate=None, name=None):
+    def __init__(self, level, pipe, capture_delegate=None, name=None):
         """
         Setup the object with a logger and a loglevel and start the thread.
         """
@@ -31,12 +28,7 @@ def __init__(self, level, capture_delegate=None, name=None):
 
         self.daemon = False
         self.level = level
-        if sys.platform == 'darwin':
-            self.fd_read, self.fd_write = pty.openpty()
-        else:
-            self.fd_read, self.fd_write = os.pipe()
-
-        self.pipeReader = os.fdopen(self.fd_read)
+        self.pipe = pipe
         self.captured_logs = []
         self.capture_delegate = capture_delegate
         self.name = name
@@ -56,43 +48,38 @@ def FindLastMatchingLine(self, matcher):
                 return match
         return None
 
-    def fileno(self):
-        """Return the write file descriptor of the pipe."""
-        return self.fd_write
-
     def run(self):
         """Run the thread, logging everything."""
-        for line in iter(self.pipeReader.readline, ''):
+        for line in iter(self.pipe.readline, b''):
+            line = line.decode('utf-8', 'ignore')
             logging.log(self.level, line.strip('\n'))
             self.captured_logs.append(line)
             if self.capture_delegate:
                 self.capture_delegate.Log(self.name, line)
 
-        self.pipeReader.close()
-
-    def close(self):
-        """Close the write end of the pipe."""
-        os.close(self.fd_write)
-
 
 class Runner:
+
     def __init__(self, capture_delegate=None):
         self.capture_delegate = capture_delegate
 
     def RunSubprocess(self, cmd, name, wait=True, dependencies=[]):
-        outpipe = LogPipe(
-            logging.DEBUG, capture_delegate=self.capture_delegate,
-            name=name + ' OUT')
-        errpipe = LogPipe(
-            logging.INFO, capture_delegate=self.capture_delegate,
-            name=name + ' ERR')
 
         if self.capture_delegate:
             self.capture_delegate.Log(name, 'EXECUTING %r' % cmd)
 
-        s = subprocess.Popen(cmd, stdout=outpipe, stderr=errpipe)
-        outpipe.close()
-        errpipe.close()
+        s = subprocess.Popen(
+            cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
+        outpipe = LogPipe(
+            logging.DEBUG, s.stdout,
+            capture_delegate=self.capture_delegate,
+            name=name + ' OUT')
+
+        errpipe = LogPipe(
+            logging.INFO, s.stderr,
+            capture_delegate=self.capture_delegate,
+            name=name + ' ERR')
 
         if not wait:
             return s, outpipe, errpipe