diff --git a/static/mobile/js/item.js b/static/mobile/js/item.js
index 7f81fa233..42c4d2cd5 100644
--- a/static/mobile/js/item.js
+++ b/static/mobile/js/item.js
@@ -129,7 +129,10 @@ async function loadData(id, args) {
             <span class="icon">${icon.down}</span>
             ${layerData.title}
         </h3>`)
-        data.layers[layer] = sortBy(data.layers[layer], ["+in", "+created"])
+        data.layers[layer] = sortBy(data.layers[layer], [
+            {key: "in", operator: "+"},
+            {key: "created", operator: "+"}
+        ])
         data.layers[layer].forEach(annotation => {
             if (pandora.url) {
                 annotation.value = annotation.value.replace(
diff --git a/static/mobile/js/utils.js b/static/mobile/js/utils.js
index a22dc75ae..e3597fd5a 100644
--- a/static/mobile/js/utils.js
+++ b/static/mobile/js/utils.js
@@ -199,10 +199,10 @@ function sortBy(array, by, map) {
         while (ret == 0 && index < by.length) {
             key = by[index].key;
             aValue = getSortValue(
-                map[key] ? map[key](a[key], a) : a[key]
+                map && map[key] ? map[key](a[key], a) : a[key]
             );
             bValue = getSortValue(
-                map[key] ? map[key](b[key], b) : b[key]
+                map && map[key] ? map[key](b[key], b) : b[key]
             );
             if ((aValue === null) != (bValue === null)) {
                 ret = aValue === null ? 1 : -1;