diff --git a/src/input.cpp b/src/input.cpp
index 78086906c5..420f840a14 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -1234,12 +1234,11 @@ void Input::shell()
   } else if (strcmp(arg[0],"putenv") == 0) {
     if (narg < 2) error->all(FLERR,"Illegal shell putenv command");
     for (int i = 1; i < narg; i++) {
-      char *ptr = strdup(arg[i]);
       rv = 0;
 #ifdef _WIN32
-      if (ptr != nullptr) rv = _putenv(ptr);
+      if (arg[i]) rv = _putenv(arg[i]);
 #else
-      if (ptr != nullptr) rv = putenv(ptr);
+      if (arg[i]) rv = putenv(arg[i]);
 #endif
       rv = (rv < 0) ? errno : 0;
       MPI_Reduce(&rv,&err,1,MPI_INT,MPI_MAX,0,world);
diff --git a/unittest/commands/test_simple_commands.cpp b/unittest/commands/test_simple_commands.cpp
index 0c6043ea84..f13ae62a73 100644
--- a/unittest/commands/test_simple_commands.cpp
+++ b/unittest/commands/test_simple_commands.cpp
@@ -312,6 +312,32 @@ TEST_F(SimpleCommandsTest, Units)
 
     TEST_FAILURE(".*ERROR: Illegal units command.*", lmp->input->one("units unknown"););
 }
+
+TEST_F(SimpleCommandsTest, Shell)
+{
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("shell putenv TEST_VARIABLE=simpletest");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+
+    char * test_var = getenv("TEST_VARIABLE");
+    ASSERT_NE(test_var, nullptr);
+    ASSERT_THAT(test_var, StrEq("simpletest"));
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("shell putenv TEST_VARIABLE=simpletest");
+    lmp->input->one("shell putenv TEST_VARIABLE2=simpletest2 OTHER_VARIABLE=2");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+
+    char * test_var2 = getenv("TEST_VARIABLE2");
+    char * other_var = getenv("OTHER_VARIABLE");
+
+    ASSERT_NE(test_var2, nullptr);
+    ASSERT_THAT(test_var2, StrEq("simpletest2"));
+
+    ASSERT_NE(other_var, nullptr);
+    ASSERT_THAT(other_var, StrEq("2"));
+}
+
 } // namespace LAMMPS_NS
 
 int main(int argc, char **argv)