diff --git a/Include/internal/pycore_pyerrors.h b/Include/internal/pycore_pyerrors.h
index 2cf1160..9dd66ae 100644
--- a/Include/internal/pycore_pyerrors.h
+++ b/Include/internal/pycore_pyerrors.h
@@ -84,6 +84,8 @@ PyAPI_FUNC(PyObject *) _PyErr_FormatFromCauseTstate(
 
 PyAPI_FUNC(int) _PyErr_CheckSignalsTstate(PyThreadState *tstate);
 
+PyAPI_FUNC(void) _Py_DumpExtensionModules(int fd, PyInterpreterState *interp);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Include/moduleobject.h b/Include/moduleobject.h
index cf9ad40..49b116c 100644
--- a/Include/moduleobject.h
+++ b/Include/moduleobject.h
@@ -84,6 +84,12 @@ typedef struct PyModuleDef{
   freefunc m_free;
 } PyModuleDef;
 
+
+// Internal C API
+#ifdef Py_BUILD_CORE
+extern int _PyModule_IsExtension(PyObject *obj);
+#endif
+
 #ifdef __cplusplus
 }
 #endif