diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index 7e2699e1b5c5bb..c10b2b302c6024 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -383,6 +383,7 @@ PyCurses_ConvertToString(PyCursesWindowObject *win, PyObject *obj,
             return 0;
         /* check for embedded null bytes */
         if (PyBytes_AsStringAndSize(*bytes, &str, NULL) < 0) {
+            Py_CLEAR(*bytes);
             return 0;
         }
         return 1;