diff --git a/config.def.h b/config.def.h
index 52059ab..da02472 100644
--- a/config.def.h
+++ b/config.def.h
@@ -32,6 +32,7 @@ static int borderpx = 2;
  */
 static char *shell = "/bin/sh";
 char *utmp = NULL;
+/* scroll program: to enable use a string like "scroll" */
 char *scroll = NULL;
 char *stty_args = "stty raw pass8 nl -echo -iexten -cstopb 38400";