1 files changed, 7 insertions, 1 deletions
diff --git a/pp.c b/pp.c
index 00b28aee41..a14b62be24 100644
--- a/pp.c
+++ b/pp.c
@@ -935,8 +935,14 @@ PP(pp_undef)
 	{
 	    /* let user-undef'd sub keep its identity */
 	    GV* const gv = CvGV((const CV *)sv);
+	    HEK * const hek = CvNAME_HEK((CV *)sv);
+	    if (hek) share_hek_hek(hek);
 	    cv_undef(MUTABLE_CV(sv));
-	    CvGV_set(MUTABLE_CV(sv), gv);
+	    if (gv) CvGV_set(MUTABLE_CV(sv), gv);
+	    else if (hek) {
+		SvANY((CV *)sv)->xcv_gv_u.xcv_hek = hek;
+		CvNAMED_on(sv);
+	    }
 	}
 	break;
     case SVt_PVGV: