--- DES.xs.orig	2013-09-05 21:54:43.776392530 -0400
+++ DES.xs	2013-09-05 21:55:30.029064319 -0400
@@ -64,8 +64,7 @@
 			output = sv_newmortal();
 		output_len = 8;
 
-		if (!SvUPGRADE(output, SVt_PV))
-			croak("cannot use output argument as lvalue");
+		(void)SvUPGRADE(output, SVt_PV);
 
 		perl_des_crypt(input, SvGROW(output, output_len), (i32 *)ks, enc_flag);