1 files changed, 1 insertions, 1 deletions
diff --git a/pp_sort.c b/pp_sort.c
index a239c01db8..d520f810dd 100644
--- a/pp_sort.c
+++ b/pp_sort.c
@@ -1516,7 +1516,7 @@ PP(pp_sort)
 	else {
 	    cv = sv_2cv(*++MARK, &stash, &gv, 0);
 	    if (cv && SvPOK(cv)) {
-		const char * const proto = SvPV_nolen_const((SV*)cv);
+		const char * const proto = SvPV_nolen_const(MUTABLE_SV(cv));
 		if (proto && strEQ(proto, "$$")) {
 		    hasargs = TRUE;
 		}