1 files changed, 11 insertions, 1 deletions
diff --git a/setup.py b/setup.py
index 3a3889cf..e7c69316 100755
--- a/setup.py
+++ b/setup.py
@@ -11,11 +11,12 @@ import contextlib
 import io
 import os
 import platform
+import re
 import shutil
+import struct
 import sys
 import tempfile
 import warnings
-import re
 
 with warnings.catch_warnings():
     warnings.simplefilter("ignore")
@@ -52,6 +53,15 @@ if POSIX:
 if BSD:
     macros.append(("PSUTIL_BSD", 1))
 
+# Needed to determine _Py_PARSE_PID in case it's missing (Python 2, PyPy).
+# Taken from Lib/test/test_fcntl.py.
+# XXX: not bullet proof as the (long long) case is missing.
+if struct.calcsize('l') == 8:
+    macros.append(('PSUTIL_SIZEOF_PID_T', '4'))  # int
+else:
+    macros.append(('PSUTIL_SIZEOF_PID_T', '8'))  # long
+
+
 sources = ['psutil/_psutil_common.c']
 if POSIX:
     sources.append('psutil/_psutil_posix.c')