diff --git a/ext/mbstring/libmbfl/filters/mbfilter_cjk.c b/ext/mbstring/libmbfl/filters/mbfilter_cjk.c
index a1ecdab9862..13635764326 100644
--- a/ext/mbstring/libmbfl/filters/mbfilter_cjk.c
+++ b/ext/mbstring/libmbfl/filters/mbfilter_cjk.c
@@ -8050,7 +8050,7 @@ const mbfl_encoding mbfl_encoding_sjis2004 = {
  *   0x7E will go to 0x7E when converting Shift-JIS to CP932.
  */
 
-static const unsigned char mblen_table_sjiswin[] = { /* 0x80-0x9F,0xE0-0xFF */
+static const unsigned char mblen_table_sjiswin[] = { /* 0x81-0x9F,0xE0-0xFF */
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
@@ -8059,7 +8059,7 @@ static const unsigned char mblen_table_sjiswin[] = { /* 0x80-0x9F,0xE0-0xFF */
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+	1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
 	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
diff --git a/ext/mbstring/tests/mb_strlen.phpt b/ext/mbstring/tests/mb_strlen.phpt
index b3fb28309bc..c8279a3c8bf 100644
--- a/ext/mbstring/tests/mb_strlen.phpt
+++ b/ext/mbstring/tests/mb_strlen.phpt
@@ -35,6 +35,13 @@ print "-- Testing illegal bytes 0x80,0xFD-FF --\n";
 print mb_strlen("\x80\xA1", 'SJIS') . "\n";
 print mb_strlen("abc\xFD\xFE\xFF", 'SJIS') . "\n";
 
+echo "== CP932 ==\n";
+print mb_strlen("\x80\xA1", "CP932") . "\n";
+// 0xFD, 0xFE, 0xFF is reserved.
+print mb_strlen("abc\xFD\xFE\xFF", 'CP932') . "\n";
+print mb_strlen("\x80\xA1", "SJIS-win") . "\n";
+print mb_strlen("abc\xFD\xFE\xFF", 'SJIS-win') . "\n";
+
 echo "== MacJapanese ==\n";
 print mb_strlen("\x80\xA1", 'MacJapanese') . "\n";
 print mb_strlen("abc\xFD\xFE\xFF", 'MacJapanese') . "\n";
@@ -107,6 +114,11 @@ try {
 -- Testing illegal bytes 0x80,0xFD-FF --
 2
 6
+== CP932 ==
+2
+6
+2
+6
 == MacJapanese ==
 2
 7