diff --git a/examples/COUPLE/lammps_mc/mc.cpp b/examples/COUPLE/lammps_mc/mc.cpp
index 24bb96641d..e62a786ac8 100644
--- a/examples/COUPLE/lammps_mc/mc.cpp
+++ b/examples/COUPLE/lammps_mc/mc.cpp
@@ -11,17 +11,16 @@
 //         mode = file, zmq
 //         modearg = filename for file, localhost:5555 for zmq
 
-#include <math.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+#include <cmath>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include "mc.h"
+#include "random_park.h"
 
 #include "cslib.h"
 using namespace CSLIB_NS;
 
-#include "mc.h"
-#include "random_park.h"
-
 void error(const char *);
 CSlib *cs_create(char *, char *);
 
diff --git a/src/MESSAGE/fix_client_md.cpp b/src/MESSAGE/fix_client_md.cpp
index 20b56e031d..9ca6df4edc 100644
--- a/src/MESSAGE/fix_client_md.cpp
+++ b/src/MESSAGE/fix_client_md.cpp
@@ -14,14 +14,15 @@
 #include <cstdio>
 #include <cstring>
 #include "fix_client_md.h"
-#include "cslib.h"
 #include "atom.h"
+#include "comm.h"
 #include "domain.h"
 #include "memory.h"
 #include "error.h"
 
-#include "comm.h"
-#include "update.h"
+// CSlib interface
+
+#include "cslib.h"
 
 using namespace LAMMPS_NS;
 using namespace CSLIB_NS;
diff --git a/src/MESSAGE/message.cpp b/src/MESSAGE/message.cpp
index 67e0a49046..a6ecf5cd60 100644
--- a/src/MESSAGE/message.cpp
+++ b/src/MESSAGE/message.cpp
@@ -11,7 +11,7 @@
    See the README file in the top-level LAMMPS directory.
 ------------------------------------------------------------------------- */
 
-#include <string.h>
+#include <cstring.h>
 #include "message.h"
 #include "error.h"
 
diff --git a/src/MESSAGE/server.cpp b/src/MESSAGE/server.cpp
index cbf769be74..c8de6de466 100644
--- a/src/MESSAGE/server.cpp
+++ b/src/MESSAGE/server.cpp
@@ -11,7 +11,7 @@
    See the README file in the top-level LAMMPS directory.
 ------------------------------------------------------------------------- */
 
-#include <string.h>
+#include <cstring.h>
 #include "server.h"
 #include "error.h"
 
diff --git a/src/MESSAGE/server_md.cpp b/src/MESSAGE/server_md.cpp
index 88fe1abe5f..9783383553 100644
--- a/src/MESSAGE/server_md.cpp
+++ b/src/MESSAGE/server_md.cpp
@@ -11,7 +11,7 @@
    See the README file in the top-level LAMMPS directory.
 ------------------------------------------------------------------------- */
 
-#include "mpi.h"
+#include <mpi.h>
 #include <cstring>
 #include "server_md.h"
 #include "atom.h"