diff --git a/engine/lexer.go b/engine/lexer.go
index 0a538146..5c0d7a65 100644
--- a/engine/lexer.go
+++ b/engine/lexer.go
@@ -701,7 +701,7 @@ func isLetterChar(r rune) bool {
 }
 
 func isSmallLetterChar(r rune) bool {
-	return unicode.In(r, unicode.Ll, unicode.Lo)
+	return unicode.In(r, unicode.Ll, unicode.Lo, unicode.Lm)
 }
 
 func isCapitalLetterChar(r rune) bool {
diff --git a/engine/lexer_test.go b/engine/lexer_test.go
index 85aa1520..a4bf81c9 100644
--- a/engine/lexer_test.go
+++ b/engine/lexer_test.go
@@ -39,6 +39,7 @@ func TestLexer_Token(t *testing.T) {
 		{input: `프롤로그`, token: Token{Kind: TokenLetterDigit, Val: `프롤로그`}},
 		{input: `برولوغ`, token: Token{Kind: TokenLetterDigit, Val: `برولوغ`}},
 		{input: `פרולוג`, token: Token{Kind: TokenLetterDigit, Val: `פרולוג`}},
+		{input: `ゴー`, token: Token{Kind: TokenLetterDigit, Val: `ゴー`}},
 
 		{input: `..`, token: Token{Kind: TokenGraphic, Val: `..`}},
 		{input: `#`, token: Token{Kind: TokenGraphic, Val: `#`}},