diff --git a/ext/mbstring/libmbfl/filters/mbfilter_sjis_2004.c b/ext/mbstring/libmbfl/filters/mbfilter_sjis_2004.c
index 169eef344f3..4f09af3b736 100644
--- a/ext/mbstring/libmbfl/filters/mbfilter_sjis_2004.c
+++ b/ext/mbstring/libmbfl/filters/mbfilter_sjis_2004.c
@@ -630,10 +630,12 @@ retry:
 			filter->status = 0;
 			CK((*filter->output_function)(s1, filter->data));
 		} else if (s1 < 0x100) { /* latin or kana */
-			if  (filter->to->no_encoding == mbfl_no_encoding_eucjp2004) {
+			if (filter->to->no_encoding == mbfl_no_encoding_eucjp2004) {
 				CK((*filter->output_function)(0x8e, filter->data));
+				CK((*filter->output_function)(s1, filter->data));
+			} else {
+				CK(mbfl_filt_conv_illegal_output(c, filter));
 			}
-			CK((*filter->output_function)(s1, filter->data));
 		} else if (s1 < 0x7f00) { /* X 0213 plane 1 */
 			if (filter->to->no_encoding == mbfl_no_encoding_sjis2004) {
 				c1 = (s1 >> 8) & 0xff;