diff --git a/src/USER-HDNNP/pair_hdnnp.cpp b/src/USER-HDNNP/pair_hdnnp.cpp
index 51f3460ab7..af64f98f75 100644
--- a/src/USER-HDNNP/pair_hdnnp.cpp
+++ b/src/USER-HDNNP/pair_hdnnp.cpp
@@ -1,6 +1,6 @@
 /* -*- c++ -*- ----------------------------------------------------------
    LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
-   http://lammps.sandia.gov, Sandia National Laboratories
+   https://www.lammps.org/ Sandia National Laboratories
    Steve Plimpton, sjplimp@sandia.gov
 
    Copyright (2003) Sandia Corporation.  Under the terms of Contract
diff --git a/src/USER-HDNNP/pair_hdnnp.h b/src/USER-HDNNP/pair_hdnnp.h
index 913da97933..9ad2969b8c 100644
--- a/src/USER-HDNNP/pair_hdnnp.h
+++ b/src/USER-HDNNP/pair_hdnnp.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- ----------------------------------------------------------
    LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
-   http://lammps.sandia.gov, Sandia National Laboratories
+   https://www.lammps.org/ Sandia National Laboratories
    Steve Plimpton, sjplimp@sandia.gov
 
    Copyright (2003) Sandia Corporation.  Under the terms of Contract