diff -r bd3647e9ac62 Modules/_cursesmodule.c
--- a/Modules/_cursesmodule.c	Tue Oct 16 13:52:53 2012 +0300
+++ b/Modules/_cursesmodule.c	Tue Oct 16 21:54:40 2012 +0300
@@ -1144,12 +1144,20 @@
         return Py_BuildValue("C", rtn);
     } else {
         const char *knp;
+        size_t size;
 #if defined(__NetBSD__)
         knp = unctrl(rtn);
 #else
         knp = keyname(rtn);
 #endif
-        return PyUnicode_FromString((knp == NULL) ? "" : knp);
+        if (knp == NULL)
+            return PyUnicode_FromStringAndSize(NULL, 0);
+        size = strlen(knp);
+        if (size > PY_SSIZE_T_MAX) {
+            PyErr_SetString(PyExc_OverflowError, "input too long");
+            return NULL;
+        }
+        return PyUnicode_DecodeLocaleAndSize(knp, (Py_ssize_t)size, NULL);
     }
 }