Merge branches/pep-0384.
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 8413641..42d0bcd 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -1398,7 +1398,7 @@
     if (buffer == NULL)
         return PyErr_NoMemory();
 
-    size = PyUnicode_AsWideChar((PyUnicodeObject*)unicode, buffer, buflen);
+    size = PyUnicode_AsWideChar(unicode, buffer, buflen);
     if (size == -1) {
         PyMem_Free(buffer);
         return NULL;