diff --git a/src/fix_numdiff.cpp b/src/fix_numdiff.cpp
index 733a639098..7d8d617b3e 100644
--- a/src/fix_numdiff.cpp
+++ b/src/fix_numdiff.cpp
@@ -16,7 +16,6 @@
 ------------------------------------------------------------------------- */
 
 #include "fix_numdiff.h"
-#include <cstring>
 #include <mpi.h>
 #include <memory.h>
 #include "atom.h"
@@ -40,7 +39,7 @@ using namespace FixConst;
 /* ---------------------------------------------------------------------- */
 
 FixNumDiff::FixNumDiff(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg), numdiff_forces(NULL), temp_f(NULL), 
+  Fix(lmp, narg, arg), numdiff_forces(NULL), temp_f(NULL),
   id_pe(NULL)
 {
   if (narg < 5) error->all(FLERR,"Illegal fix numdiff command");
@@ -52,8 +51,7 @@ FixNumDiff::FixNumDiff(LAMMPS *lmp, int narg, char **arg) :
 
   nevery = force->inumeric(FLERR,arg[3]);
   delta = force->numeric(FLERR,arg[4]);
-  if (nevery <= 0 || delta <= 0.0) 
-    error->all(FLERR,"Illegal fix numdiff command");
+  if (nevery <= 0 || delta <= 0.0) error->all(FLERR,"Illegal fix numdiff command");
 
   int n = strlen(id) + 6;
   id_pe = new char[n];
@@ -104,8 +102,7 @@ void FixNumDiff::init()
 {
   // require consecutive atom IDs
 
-  if (!atom->tag_enable || !atom->tag_consecutive()) 
-    error->all(FLERR,"Fix numdiff requires consecutive atom IDs");
+  if (!atom->tag_enable || !atom->tag_consecutive()) error->all(FLERR,"Fix numdiff requires consecutive atom IDs");
 
   // check for PE compute