diff --git a/Python/traceback.c b/Python/traceback.c
index 9b23f45..284c181 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -234,7 +234,7 @@ _PyTraceBack_FromFrame(PyObject *tb_next, PyFrameObject *frame)
     assert(tb_next == NULL || PyTraceBack_Check(tb_next));
     assert(frame != NULL);
 
-    return tb_create_raw((PyTracebackObject *)tb_next, frame, frame->f_lasti*2,
+    return tb_create_raw((PyTracebackObject *)tb_next, frame, frame->f_lasti*sizeof(_Py_CODEUNIT),
                          PyFrame_GetLineNumber(frame));
 }