diff --git a/src/viewport.js b/src/viewport.js
index bf6ece60..2df47df9 100644
--- a/src/viewport.js
+++ b/src/viewport.js
@@ -514,7 +514,7 @@ $.Viewport.prototype = {
      * @param {OpenSeadragon.Rect} bounds
      * @returns {OpenSeadragon.Rect} constrained bounds.
      */
-     _applyBoundaryConstraints: function(bounds) {
+    _applyBoundaryConstraints: function(bounds) {
         var newBounds = new $.Rect(
                 bounds.x,
                 bounds.y,