diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index aa97301..8974d37 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -46,7 +46,7 @@ PyFrame_GetLineNumber(PyFrameObject *f)
         return f->f_lineno;
     }
     else {
-        return PyCode_Addr2Line(f->f_code, f->f_lasti*2);
+        return PyCode_Addr2Line(f->f_code, f->f_lasti*sizeof(_Py_CODEUNIT));
     }
 }
 
@@ -68,7 +68,7 @@ frame_getlasti(PyFrameObject *f, void *closure)
     if (f->f_lasti < 0) {
         return PyLong_FromLong(-1);
     }
-    return PyLong_FromLong(f->f_lasti*2);
+    return PyLong_FromLong(f->f_lasti*sizeof(_Py_CODEUNIT));
 }
 
 
diff --git a/Python/ceval.c b/Python/ceval.c
index 686250e..624baf5 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -5490,7 +5490,7 @@ call_trace(Py_tracefunc func, PyObject *obj,
     }
     else {
         initialize_trace_info(trace_info, frame);
-        frame->f_lineno = _PyCode_CheckLineNumber(frame->f_lasti*2, &trace_info->bounds);
+        frame->f_lineno = _PyCode_CheckLineNumber(frame->f_lasti*sizeof(_Py_CODEUNIT), &trace_info->bounds);
     }
     result = func(obj, frame, what, arg);
     frame->f_lineno = 0;
@@ -5530,8 +5530,8 @@ maybe_call_line_trace(Py_tracefunc func, PyObject *obj,
        then call the trace function if we're tracing source lines.
     */
     initialize_trace_info(trace_info, frame);
-    int lastline = _PyCode_CheckLineNumber(instr_prev*2, &trace_info->bounds);
-    int line = _PyCode_CheckLineNumber(frame->f_lasti*2, &trace_info->bounds);
+    int lastline = _PyCode_CheckLineNumber(instr_prev*sizeof(_Py_CODEUNIT), &trace_info->bounds);
+    int line = _PyCode_CheckLineNumber(frame->f_lasti*sizeof(_Py_CODEUNIT), &trace_info->bounds);
     if (line != -1 && frame->f_trace_lines) {
         /* Trace backward edges or if line number has changed */
         if (frame->f_lasti < instr_prev || line != lastline) {
@@ -6494,7 +6494,7 @@ maybe_dtrace_line(PyFrameObject *frame,
        instruction window, reset the window.
     */
     initialize_trace_info(trace_info, frame);
-    int line = _PyCode_CheckLineNumber(frame->f_lasti*2, &trace_info->bounds);
+    int line = _PyCode_CheckLineNumber(frame->f_lasti*sizeof(_Py_CODEUNIT), &trace_info->bounds);
     /* If the last instruction falls at the start of a line or if
        it represents a jump backwards, update the frame's line
        number and call the trace function. */
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));
 }