diff --git a/tests/python/pants_test/process/test_lock.py b/tests/python/pants_test/process/test_lock.py
index <HASH>..<HASH> 100644
--- a/tests/python/pants_test/process/test_lock.py
+++ b/tests/python/pants_test/process/test_lock.py
@@ -55,7 +55,7 @@ class TestOwnerPrintingInterProcessFileLock(unittest.TestCase):
     self.lock_process.start()
     self.lock_held.wait()
     self.assertTrue(os.path.exists(self.lock.message_path))
-    with open(self.lock.message_path, 'rb') as f:
+    with open(self.lock.message_path, 'r') as f:
       message_content = f.read()
     self.assertIn(str(self.lock_process.pid), message_content)
Python 3 fixes - fix process test byte issue (#<I>)