1 files changed, 5 insertions, 3 deletions

diff --git a/js/tools/ZoomTool.js b/js/tools/ZoomTool.js
index 73297d16..4b6705c1 100644
--- a/js/tools/ZoomTool.js
+++ b/js/tools/ZoomTool.js
@@ -140,9 +140,11 @@ exports.ZoomTool = Montage.create(DrawingTool, {
         {
                 value : function (event)
                 {
-                        // check for some reasonable amount of mouse movement
-                        var dx = Math.abs(event.layerX - this.downPoint.x),
-                                dy = Math.abs(event.layerY - this.downPoint.y);
+            var point = webkitConvertPointFromPageToNode(this.application.ninja.stage.canvas,
+                                                                    new WebKitPoint(event.pageX, event.pageY));
+            // check for some reasonable amount of mouse movement
+                        var dx = Math.abs(point.x - this.downPoint.x),
+                                dy = Math.abs(point.y - this.downPoint.y);
 
                         if ((dx >= 4) || (dy >= 4))
                         {