diff --git a/Mac/Modules/cf/_CFmodule.c b/Mac/Modules/cf/_CFmodule.c
index 1f44a8eaef8..85433319fc2 100644
--- a/Mac/Modules/cf/_CFmodule.c
+++ b/Mac/Modules/cf/_CFmodule.c
@@ -2349,7 +2349,7 @@ static PyObject *CFStringRefObj_CFStringGetUnicode(CFStringRefObject *_self, PyO
 	range.length = size;
 	if( data == NULL ) return PyErr_NoMemory();
 	CFStringGetCharacters(_self->ob_itself, range, data);
-	_res = (PyObject *)PyUnicode_FromUnicode(data, size);
+	_res = (PyObject *)PyUnicode_FromUnicode(data, size-1);
 	free(data);
 	return _res;
 
diff --git a/Mac/Modules/cf/cfsupport.py b/Mac/Modules/cf/cfsupport.py
index c244c727dc7..f236e6d374e 100644
--- a/Mac/Modules/cf/cfsupport.py
+++ b/Mac/Modules/cf/cfsupport.py
@@ -575,7 +575,7 @@ def outputRepr(self):
 range.length = size;
 if( data == NULL ) return PyErr_NoMemory();
 CFStringGetCharacters(_self->ob_itself, range, data);
-_res = (PyObject *)PyUnicode_FromUnicode(data, size);
+_res = (PyObject *)PyUnicode_FromUnicode(data, size-1);
 free(data);
 return _res;
 """