diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 1f2d919..77f8dd5 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -1897,7 +1897,7 @@
     size = PyBytes_GET_SIZE(output);
     data = PyBytes_AS_STRING(output);
     if (size != strlen(data)) {
-        PyErr_SetString(PyExc_TypeError, "embedded NULL character");
+        PyErr_SetString(PyExc_TypeError, "embedded NUL character");
         Py_DECREF(output);
         return 0;
     }