diff --git a/src/attacher.c b/src/attacher.c
index 2565a0f..9e916eb 100644
--- a/src/attacher.c
+++ b/src/attacher.c
@@ -37,6 +37,10 @@
 
 #include <pwd.h>
 
+#ifndef NOSYSLOG
+#include <syslog.h>
+#endif
+
 static int WriteMessage __P((int, struct msg *));
 static sigret_t AttacherSigInt __P(SIGPROTOARG);
 #if defined(SIGWINCH) && defined(TIOCGWINSZ)
@@ -1001,6 +1005,9 @@ screen_builtin_lck()
       bzero(cp1, strlen(cp1));
     }
   bzero(cp1, strlen(cp1));
+#ifndef NOSYSLOG
+  syslog(LOG_AUTHPRIV | LOG_NOTICE, "authentication success; logname=%s uid=%d", ppp->pw_name, ppp->pw_uid);
+#endif
   debug("password ok.\n");
 }