1 files changed, 1 insertions, 3 deletions
diff --git a/setup.py b/setup.py
index b96961073b..c278f08b8e 100644
--- a/setup.py
+++ b/setup.py
@@ -784,9 +784,7 @@ class PyBuildExt(build_ext):
         self.add(Extension('syslog', ['syslogmodule.c']))
 
         # Python interface to subinterpreter C-API.
-        self.add(Extension('_xxsubinterpreters',
-                           ['_xxsubinterpretersmodule.c'],
-                           define_macros=[('Py_BUILD_CORE', '')]))
+        self.add(Extension('_xxsubinterpreters', ['_xxsubinterpretersmodule.c']))
 
         #
         # Here ends the simple stuff.  From here on, modules need certain