diff --git a/src/MOLECULE/bond_nonlinear.cpp b/src/MOLECULE/bond_nonlinear.cpp
index 72e4580fcd..8f0616e03e 100644
--- a/src/MOLECULE/bond_nonlinear.cpp
+++ b/src/MOLECULE/bond_nonlinear.cpp
@@ -14,6 +14,7 @@
 #include "bond_nonlinear.h"
 #include <mpi.h>
 #include <cmath>
+#include <cstring>
 #include "atom.h"
 #include "neighbor.h"
 #include "comm.h"