diff --git a/helper/compare_dbs.pl b/helper/compare_dbs.pl
index 3f675e0..6ad1932 100755
--- a/helper/compare_dbs.pl
+++ b/helper/compare_dbs.pl
@@ -246,7 +246,7 @@ __USAGE__
 }
 
 sub is_exception {
-    my $exceptions, $type, $schema, $element, $attr) = @_;
+    my ($exceptions, $type, $schema, $element, $attr) = @_;
 
     $attr //= '';
     foreach my $exception (@{$exceptions}) {