diff --git a/circ/circulation.pl b/circ/circulation.pl
index bf7ed246e4..cd0469cd1e 100755
--- a/circ/circulation.pl
+++ b/circ/circulation.pl
@@ -131,6 +131,7 @@ if ( C4::Context->preference("AutoSwitchPatron") && $barcode ) {
         $findborrower = $barcode;
         undef $barcode;
         undef $borrowernumber;
+        undef $patron;
         $barcodes = [];
         $autoswitched = 1;
     }