diff --git a/main.go b/main.go
index be0d755..b1ffd5b 100644
--- a/main.go
+++ b/main.go
@@ -34,6 +34,7 @@ func main() {
 		u, p, ok := r.BasicAuth()
 		if !ok || subtle.ConstantTimeCompare([]byte(u), []byte(username)) != 1 ||
 			subtle.ConstantTimeCompare([]byte(p), []byte(password)) != 1 {
+			log.Printf("unauthorized request from %s", r.RemoteAddr)
 			w.Header().Set("WWW-Authenticate", `Basic realm="pz8-relay"`)
 			http.Error(w, "unauthorized", http.StatusUnauthorized)
 			return