diff --git a/lib/convenience/thumb.js b/lib/convenience/thumb.js
index 38d4e74c..6c029cee 100644
--- a/lib/convenience/thumb.js
+++ b/lib/convenience/thumb.js
@@ -23,7 +23,7 @@ module.exports = function (proto) {
     name = args.shift();
     quality = args.shift() || 63;
     align = args.shift() || 'topleft';
-    var interlace = args.shift() ? 'Line' : 'None';
+    var interlace = args.shift() || 'None';
 
     self.size(function (err, size) {
       if (err) {