diff --git a/src/MANYBODY/pair_atm.cpp b/src/MANYBODY/pair_atm.cpp
index e960398ab30b219975b103439c0dd927aaaa82ce..c23aa6560d6453aaeb1a949bca0e6ea7030137a1 100644
--- a/src/MANYBODY/pair_atm.cpp
+++ b/src/MANYBODY/pair_atm.cpp
@@ -15,10 +15,10 @@
    Contributing author: Sergey Lishchuk
 ------------------------------------------------------------------------- */
 
-#include "pair_atm.h"
 
-#include <math.h>
+#include <cmath>
 
+#include "pair_atm.h"
 #include "atom.h"
 #include "citeme.h"
 #include "comm.h"