diff --git a/lexers/a/arduino.go b/lexers/a/arduino.go
index e00b378..b0cd8c9 100644
--- a/lexers/a/arduino.go
+++ b/lexers/a/arduino.go
@@ -6,7 +6,7 @@ import (
 )
 
 // Arduino lexer.
-var arduino = internal.Register(MustNewLexer(
+var Arduino = internal.Register(MustNewLexer(
 	&Config{
 		Name:      "Arduino",
 		Aliases:   []string{"arduino"},