diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index f206895..39a6b2e 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -581,7 +581,7 @@
    MemoryError. */
 
 PyAPI_FUNC(wchar_t*) PyUnicode_AsWideCharString(
-    PyUnicodeObject *unicode,   /* Unicode object */
+    PyObject *unicode,          /* Unicode object */
     Py_ssize_t *size            /* number of characters of the result */
     );