diff --git a/ext/etc/etc.c b/ext/etc/etc.c
index 157c6772ec..e2d621547e 100644
--- a/ext/etc/etc.c
+++ b/ext/etc/etc.c
@@ -1311,4 +1311,8 @@ Init_etc(void)
     rb_extend_object(sGroup, rb_mEnumerable);
     rb_define_singleton_method(sGroup, "each", etc_each_group, 0);
 #endif
+
+#if defined(HAVE_GETPWENT) || defined(HAVE_GETGRENT)
+    (void)safe_setup_str;
+#endif
 }