--- Modules/main.c
+++ Modules/main.c
@@ -575,6 +575,10 @@
             PySys_AddWarnOptionUnicode(PyList_GET_ITEM(warning_options, i));
         }
     }
+    if (Py_BytesWarningFlag > 1)
+        PySys_AddWarnOption(L"error::BytesWarning");
+    else if (Py_BytesWarningFlag)
+        PySys_AddWarnOption(L"default::BytesWarning");
 
     if (command == NULL && module == NULL && _PyOS_optind < argc &&
         wcscmp(argv[_PyOS_optind], L"-") != 0)
--- Python/_warnings.c
+++ Python/_warnings.c
@@ -981,10 +981,10 @@
 static PyObject *
 init_filters(void)
 {
-    PyObject *filters = PyList_New(5);
+    PyObject *filters = PyList_New(4);
     unsigned int pos = 0;  /* Post-incremented in each use. */
     unsigned int x;
-    const char *bytes_action, *resource_action;
+    const char *resource_action;
 
     if (filters == NULL)
         return NULL;
@@ -995,14 +995,6 @@
                     create_filter(PyExc_PendingDeprecationWarning, "ignore"));
     PyList_SET_ITEM(filters, pos++,
                     create_filter(PyExc_ImportWarning, "ignore"));
-    if (Py_BytesWarningFlag > 1)
-        bytes_action = "error";
-    else if (Py_BytesWarningFlag)
-        bytes_action = "default";
-    else
-        bytes_action = "ignore";
-    PyList_SET_ITEM(filters, pos++, create_filter(PyExc_BytesWarning,
-                    bytes_action));
     /* resource usage warnings are enabled by default in pydebug mode */
 #ifdef Py_DEBUG
     resource_action = "always";