diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index 154c26f..07995ec 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -86,8 +86,7 @@
 		if (len > 0 &&
 		    (isalpha((unsigned char)*rec) || /* identifier? */
 		     *rec == '_' ||	/* also identifier? */
-		     *rec == '(' ||	/* lisp defun? */
-		     *rec == '#')) {	/* #define? */
+		     *rec == '$')) {	/* mysterious GNU diff's invention */
 			if (len > sz)
 				len = sz;
 			while (0 < len && isspace((unsigned char)rec[len - 1]))