1 files changed, 2 insertions, 2 deletions
diff --git a/pp.c b/pp.c
index eaf6a85277..5910e8691d 100644
--- a/pp.c
+++ b/pp.c
@@ -970,10 +970,10 @@ PP(pp_undef)
     case SVt_NULL:
 	break;
     case SVt_PVAV:
-	av_undef(MUTABLE_AV(sv));
+	av_undef(MUTABLE_AV(sv_2mortal(SvREFCNT_inc_simple_NN(sv))));
 	break;
     case SVt_PVHV:
-	hv_undef(MUTABLE_HV(sv));
+	hv_undef(MUTABLE_HV(sv_2mortal(SvREFCNT_inc_simple_NN(sv))));
 	break;
     case SVt_PVCV:
 	if (cv_const_sv((const CV *)sv))