diff --git a/Koha/Exceptions/Metadata.pm b/Koha/Exceptions/Metadata.pm
index 75013885af..7d2e02ff1c 100644
--- a/Koha/Exceptions/Metadata.pm
+++ b/Koha/Exceptions/Metadata.pm
@@ -40,7 +40,8 @@ sub full_message {
         if ( $self->isa('Koha::Exceptions::Metadata::Invalid') ) {
             $msg = sprintf(
                 "Invalid data, cannot decode metadata object (biblio_metadata.id=%s, biblionumber=%s, format=%s, schema=%s, decoding_error='%s')",
-                $self->id, $self->biblionumber, $self->format, $self->schema, $self->decoding_error
+                $self->id // '', $self->biblionumber // '', $self->format // '', $self->schema // '',
+                $self->decoding_error // ''
             );
         }
     }