diff --git a/browser/components/customizableui/src/CustomizeMode.jsm b/browser/components/customizableui/src/CustomizeMode.jsm
index 9f2d6869cd05..64bce1427821 100644
--- a/browser/components/customizableui/src/CustomizeMode.jsm
+++ b/browser/components/customizableui/src/CustomizeMode.jsm
@@ -234,7 +234,7 @@ CustomizeMode.prototype = {
       this._showPanelCustomizationPlaceholders();
 
       yield this._wrapToolbarItems();
-      yield this.populatePalette();
+      this.populatePalette();
 
       this.visiblePalette.addEventListener("dragstart", this, true);
       this.visiblePalette.addEventListener("dragover", this, true);
@@ -647,7 +647,7 @@ CustomizeMode.prototype = {
     let fragment = this.document.createDocumentFragment();
     let toolboxPalette = this.window.gNavToolbox.palette;
 
-    return Task.spawn(function() {
+    try {
       let unusedWidgets = CustomizableUI.getUnusedWidgets(toolboxPalette);
       for (let widget of unusedWidgets) {
         let paletteItem = this.makePaletteItem(widget, "palette");
@@ -657,7 +657,9 @@ CustomizeMode.prototype = {
       this.visiblePalette.appendChild(fragment);
       this._stowedPalette = this.window.gNavToolbox.palette;
       this.window.gNavToolbox.palette = this.visiblePalette;
-    }.bind(this)).then(null, ERROR);
+    } catch (ex) {
+      ERROR(ex);
+    }
   },
 
   //XXXunf Maybe this should use -moz-element instead of wrapping the node?
@@ -985,7 +987,7 @@ CustomizeMode.prototype = {
       CustomizableUI.reset();
 
       yield this._wrapToolbarItems();
-      yield this.populatePalette();
+      this.populatePalette();
 
       this.persistCurrentSets(true);
 
@@ -1011,7 +1013,7 @@ CustomizeMode.prototype = {
       CustomizableUI.undoReset();
 
       yield this._wrapToolbarItems();
-      yield this.populatePalette();
+      this.populatePalette();
 
       this.persistCurrentSets(true);