diff --git a/ext/mbstring/libmbfl/filters/mbfilter_sjis_mac.c b/ext/mbstring/libmbfl/filters/mbfilter_sjis_mac.c
index bcc84dd2a9f..7962639d341 100644
--- a/ext/mbstring/libmbfl/filters/mbfilter_sjis_mac.c
+++ b/ext/mbstring/libmbfl/filters/mbfilter_sjis_mac.c
@@ -268,6 +268,11 @@ static int mbfl_filt_conv_sjis_mac_wchar_flush(mbfl_convert_filter *filter)
 	if (filter->status == 1) {
 		CK((*filter->output_function)(MBFL_BAD_INPUT, filter->data));
 	}
+
+	if (filter->flush_function) {
+		(*filter->flush_function)(filter->data);
+	}
+
 	return 0;
 }