                 let aliases = gir.aliases.filter{!blacklist.contains($0.name)}.map(swiftCode).joined(separator: "\n\n")
                 if let dir = outputDirectory {
                     let f = "\(dir)/\(node)-aliases.swift"
-                    let output = prefix + aliases
+                    let output = preamble + aliases
                     write(output, to: f)
                 } else {
                     outq.async(group: queues) { print(aliases) } }

                let bitfields = gir.bitfields.filter{!blacklist.contains($0.name)}.map(swiftCode).joined(separator: "\n\n")
                if let dir = outputDirectory {
                    let f = "\(dir)/\(node)-bitfields.swift"
                    let output = prefix + bitfields
                    write(output, to: f)
                } else { outq.async(group: queues) { print(bitfields) } }
            }

            background.async(group: queues) {
                let callbacks = gir.callbacks.filter{!blacklist.contains($0.name)}.map(swiftCallbackAliasCode).joined(separator: "\n\n")
                if let dir = outputDirectory {
                    let output = preamble + callbacks
                    let f = "\(dir)/\(node)-callbacks.swift"
                    write(output, to: f)
                } else { outq.async(group: queues) { print(callbacks) } }
