diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -5899,6 +5899,7 @@ Delete an environment variable.");
 static PyObject *
 posix_unsetenv(PyObject *self, PyObject *args)
 {
+    int rc;
 #ifdef MS_WINDOWS
     char *s1;
 
@@ -5914,7 +5915,10 @@ posix_unsetenv(PyObject *self, PyObject 
     s1 = PyBytes_AsString(os1);
 #endif
 
-    unsetenv(s1);
+    rc = unsetenv(s1);
+    fprintf(stderr, "unsetenv returned %d\n", rc);
+    if (rc != 0)
+        perror("error message");
 
     /* Remove the key from posix_putenv_garbage;
      * this will cause it to be collected.  This has to
@@ -8187,6 +8191,9 @@ INITFUNC(void)
 #ifdef HAVE_PUTENV
     if (posix_putenv_garbage == NULL)
         posix_putenv_garbage = PyDict_New();
+    Py_XINCREF(posix_putenv_garbage);
+    if (posix_putenv_garbage == NULL || PyModule_AddObject(m, "posix_putenv_garbage", posix_putenv_garbage) != 0)
+        return NULL;
 #endif
 
     if (!initialized) {