1 files changed, 2 insertions, 0 deletions
diff --git a/Bugzilla/Bug.pm b/Bugzilla/Bug.pm
index 6f22d967c..1d12ee2cf 100644
--- a/Bugzilla/Bug.pm
+++ b/Bugzilla/Bug.pm
@@ -296,6 +296,8 @@ sub check {
     my $class = shift;
     my ($id, $field) = @_;
 
+    ThrowUserError('improper_bug_id_field_value', { field => $field }) unless defined $id;
+
     # Bugzilla::Bug throws lots of special errors, so we don't call
     # SUPER::check, we just call our new and do our own checks.
     my $self = $class->new(trim($id));