diff --git a/Python/pystrhex.c b/Python/pystrhex.c
index b8f3146..a20e3074 100644
--- a/Python/pystrhex.c
+++ b/Python/pystrhex.c
@@ -47,14 +47,14 @@
     return retval;
 }
 
-PyObject *_Py_strhex(const char* argbuf, const Py_ssize_t arglen)
+PyAPI_FUNC(PyObject *) _Py_strhex(const char* argbuf, const Py_ssize_t arglen)
 {
     return _Py_strhex_impl(argbuf, arglen, 0);
 }
 
 /* Same as above but returns a bytes() instead of str() to avoid the
  * need to decode the str() when bytes are needed. */
-PyObject *_Py_strhex_bytes(const char* argbuf, const Py_ssize_t arglen)
+PyAPI_FUNC(PyObject *) _Py_strhex_bytes(const char* argbuf, const Py_ssize_t arglen)
 {
     return _Py_strhex_impl(argbuf, arglen, 1);
 }