diff --git a/C.xs b/C.xs
index 504705aff..f30d8800e 100644
--- a/C.xs
+++ b/C.xs
@@ -674,6 +674,14 @@ PadnameGEN(padn)
     OUTPUT:
        RETVAL
 
+bool
+PadnameIsUndef(padn)
+       B::PADNAME      padn
+    CODE:
+        RETVAL = padn == &PL_padname_undef ? TRUE : FALSE;
+    OUTPUT:
+       RETVAL
+
 MODULE = B  PACKAGE = B::INVLIST    PREFIX = Invlist
 
 int
diff --git a/lib/B/C/OverLoad/B/PADNAME.pm b/lib/B/C/OverLoad/B/PADNAME.pm
index dd07914eb..ebb71115f 100644
--- a/lib/B/C/OverLoad/B/PADNAME.pm
+++ b/lib/B/C/OverLoad/B/PADNAME.pm
@@ -13,15 +13,17 @@ our $MAX_PADNAME_LENGTH = 1;
 sub do_save {
     my ( $pn, $fullname ) = @_;
 
+    return q[&PL_padname_undef] if $pn->IsUndef;
+
     my ( $ix, $sym ) = padnamesect()->reserve($pn);
     padnamesect()->debug( $fullname, $pn );
 
     my $refcnt = $pn->REFCNT;
+    my $pv     = $pn->PVX;
 
-    my $pv = $pn->PVX;
     my $xpadn_str = cstring($pv) || '{0}';
 
-    my $xpadn_pv = $ix ? sprintf( "((char*)%s)+STRUCT_OFFSET(struct padname_with_str, xpadn_str[0])", $sym ) : 'NULL';
+    my $xpadn_pv = sprintf( "((char*)%s)+STRUCT_OFFSET(struct padname_with_str, xpadn_str[0])", $sym );
 
     # Track the largest padname length to determine the size of the struct.
     my $xpadn_len = $pn->LEN;