1 files changed, 4 insertions, 0 deletions
diff --git a/setup.py b/setup.py
index ba0a762..6f9a397 100644
--- a/setup.py
+++ b/setup.py
@@ -755,6 +755,10 @@ class PyBuildExt(build_ext):
             ['_xxtestfuzz/_xxtestfuzz.c', '_xxtestfuzz/fuzzer.c'])
         )
 
+        # Python interface to subinterpreter C-API.
+        exts.append(Extension('_xxsubinterpreters', ['_xxsubinterpretersmodule.c'],
+                              define_macros=[('Py_BUILD_CORE', '')]))
+
         #
         # Here ends the simple stuff.  From here on, modules need certain
         # libraries, are platform-specific, or present other surprises.