diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 2250f45..d6cc8b5 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -1811,7 +1811,7 @@
 
         wchar = _Py_char2wchar(s, &len);
         if (wchar == NULL)
-            return NULL;
+            return PyErr_NoMemory();
 
         unicode = PyUnicode_FromWideChar(wchar, len);
         PyMem_Free(wchar);