diff --git a/environment.h b/environment.h
index 3496474cce..a8b06674eb 100644
--- a/environment.h
+++ b/environment.h
@@ -8,7 +8,6 @@ struct strvec;
  * The character that begins a commented line in user-editable file
  * that is subject to stripspace.
  */
-#define comment_line_char (comment_line_str[0])
 extern const char *comment_line_str;
 extern int auto_comment_line_char;