diff --git a/src/PLUMED/fix_plumed.cpp b/src/PLUMED/fix_plumed.cpp
index 7a142b57f8..137cd580a8 100644
--- a/src/PLUMED/fix_plumed.cpp
+++ b/src/PLUMED/fix_plumed.cpp
@@ -41,7 +41,7 @@
 #if defined(__PLUMED_DEFAULT_KERNEL)
 #define PLUMED_QUOTE_DIRECT(name) #name
 #define PLUMED_QUOTE(macro) PLUMED_QUOTE_DIRECT(macro)
-static char plumed_default_kernel[] = "PLUMED_KERNEL=" PLUMED_QUOTE(__PLUMED_DEFAULT_KERNEL);
+static const char plumed_default_kernel[] = "PLUMED_KERNEL=" PLUMED_QUOTE(__PLUMED_DEFAULT_KERNEL);
 #endif
 
 /* -------------------------------------------------------------------- */
@@ -68,7 +68,7 @@ FixPlumed::FixPlumed(LAMMPS *lmp, int narg, char **arg) :
 
 #if defined(__PLUMED_DEFAULT_KERNEL)
   if (getenv("PLUMED_KERNEL") == nullptr)
-    putenv(plumed_default_kernel);
+    platform::putenv(plumed_default_kernel);
 #endif
 
   p=new PLMD::Plumed;
diff --git a/src/input.cpp b/src/input.cpp
index 833dbaa6df..c9b471f599 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -1241,20 +1241,7 @@ void Input::shell()
     if (narg < 2) error->all(FLERR,"Illegal shell putenv command");
     for (int i = 1; i < narg; i++) {
       rv = 0;
-#ifdef _WIN32
-      if (arg[i]) rv = _putenv(utils::strdup(arg[i]));
-#else
-      if (arg[i]) {
-        std::string vardef(arg[i]);
-        auto found = vardef.find_first_of('=');
-        if (found == std::string::npos) {
-          rv = setenv(vardef.c_str(),"",1);
-        } else {
-          rv = setenv(vardef.substr(0,found).c_str(),
-                      vardef.substr(found+1).c_str(),1);
-        }
-      }
-#endif
+      if (arg[i]) rv = platform::putenv(arg[i]);
       rv = (rv < 0) ? errno : 0;
       MPI_Reduce(&rv,&err,1,MPI_INT,MPI_MAX,0,world);
       if (me == 0 && err != 0) {
diff --git a/src/lammps.cpp b/src/lammps.cpp
index 83a7115dcf..e24c42689f 100644
--- a/src/lammps.cpp
+++ b/src/lammps.cpp
@@ -134,15 +134,16 @@ LAMMPS::LAMMPS(int narg, char **arg, MPI_Comm communicator) :
   init_pkg_lists();
 
 #if defined(LMP_PYTHON) && defined(_WIN32)
-  // if the LAMMPSHOME environment variable is set, it should point
+  // If the LAMMPSHOME environment variable is set, it should point
   // to the location of the LAMMPS installation tree where we bundle
   // the matching Python installation for use with the PYTHON package.
-  // this is currently only used on Windows with the windows installer packages
+  // This is currently only used on Windows with the Windows installer packages
   const char *lmpenv = getenv("LAMMPSHOME");
   if (lmpenv) {
-    _putenv(utils::strdup(fmt::format("PYTHONHOME={}",lmpenv)));
+    platform::putenv(fmt::format("PYTHONHOME={}",lmpenv));
   }
 #endif
+
   // check if -mpicolor is first arg
   // if so, then 2 apps were launched with one mpirun command
   //   this means passed communicator (e.g. MPI_COMM_WORLD) is bigger than LAMMPS