diff --git a/src/runtime/python/pypgf.c b/src/runtime/python/pypgf.c
index e44bebae7..f15c79fa7 100644
--- a/src/runtime/python/pypgf.c
+++ b/src/runtime/python/pypgf.c
@@ -1040,6 +1040,8 @@ static PyTypeObject pgf_EmbeddedGrammarType = {
     0,                                        /*tp_new */
 };
 
+PyAPI_FUNC(int) _PyImport_SetModule(PyObject *name, PyObject *module);
+
 static PyObject*
 PGF_embed(PGFObject* self, PyObject *modname)
 {