diff --git a/openbox/openbox.c b/openbox/openbox.c
index 6f47fbd0..ff226af4 100644
--- a/openbox/openbox.c
+++ b/openbox/openbox.c
@@ -512,7 +512,9 @@ static void remove_args(gint *argc, gchar **argv, gint index, gint num)
 static void parse_env()
 {
     /* unset this so we don't pass it on unknowingly */
-    putenv("DESKTOP_STARTUP_ID");
+    gchar *s = g_strdup("DESKTOP_STARTUP_ID");
+    putenv(s);
+    g_free(s);
 }
 
 static void parse_args(gint *argc, gchar **argv)