diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 2da5d41..9dea4b5 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -5662,6 +5662,7 @@
 	new = PyString_AS_STRING(newstr);
 	PyOS_snprintf(new, len, "%s=%s", s1, s2);
 	if (putenv(new)) {
+                Py_DECREF(newstr);
                 posix_error();
                 return NULL;
 	}