diff -up at-3.1.10/atd.c.bla at-3.1.10/atd.c
--- at-3.1.10/atd.c.bla	2008-07-18 15:18:35.000000000 +0200
+++ at-3.1.10/atd.c	2008-07-18 15:19:41.000000000 +0200
@@ -643,7 +643,7 @@ run_file(const char *filename, uid_t uid
 #if defined(SENDMAIL)
 	    execl(SENDMAIL, "sendmail", mailname, (char *) NULL);
 #else
-#error      "No mail command specified."
+		perr("No mail command specified.");
 #endif
 	    perr("Exec failed for mail command");