diff --git a/src/octoprint/static/js/app/dataupdater.js b/src/octoprint/static/js/app/dataupdater.js
index ec915b59..71f1d1a3 100644
--- a/src/octoprint/static/js/app/dataupdater.js
+++ b/src/octoprint/static/js/app/dataupdater.js
@@ -106,6 +106,7 @@ function DataUpdater(allViewModels) {
     self._onSlicingProgress = function(event) {
         $("#gcode_upload_progress").find(".bar").text(_.sprintf(gettext("Slicing ... (%(percentage)d%%)"), {percentage: Math.round(event.data["progress"])}));
 
+        var data = event.data;
         callViewModels(self.allViewModels, "onSlicingProgress", [
             data["slicer"],
             data["model_path"],