diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 81adf5d..9337f5c 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -899,6 +899,12 @@
 	}
 }
 
+int
+PySys_HasWarnOptions(void)
+{
+    return (warnoptions != NULL && (PyList_Size(warnoptions) > 0)) ? 1 : 0;
+}
+
 /* XXX This doc string is too long to be a single string literal in VC++ 5.0.
    Two literals concatenated works just fine.  If you have a K&R compiler
    or other abomination that however *does* understand longer strings,
@@ -1101,6 +1107,7 @@
 #endif
 	/* {"unbuffered",		"-u"}, */
 	/* {"skip_first",		"-x"}, */
+	{"bytes_warning", "-b"},
 	{0}
 };
 
@@ -1144,6 +1151,7 @@
 #endif
 	/* SetFlag(saw_unbuffered_flag); */
 	/* SetFlag(skipfirstline); */
+    SetFlag(Py_BytesWarningFlag);
 #undef SetFlag
 
 	if (PyErr_Occurred()) {