diff --git a/src/lib/viewers/archive/ArchiveExplorer.js b/src/lib/viewers/archive/ArchiveExplorer.js
index 8541ac219..eb4a1e9e0 100644
--- a/src/lib/viewers/archive/ArchiveExplorer.js
+++ b/src/lib/viewers/archive/ArchiveExplorer.js
@@ -167,7 +167,11 @@ class ArchiveExplorer extends React.Component {
             return itemList;
         }
 
-        const sortedItems = itemList.sort((a, b) => {
+        const sortedItems = itemList.sort((a = {}, b = {}) => {
+            if (!a[sortBy] || !b[sortBy]) {
+                return -1;
+            }
+
             if (typeof a[sortBy] === 'number' && typeof b[sortBy] === 'number') {
                 return a[sortBy] - b[sortBy];
             }
diff --git a/src/lib/viewers/archive/__tests__/ArchiveExplorer-test-react.js b/src/lib/viewers/archive/__tests__/ArchiveExplorer-test-react.js
index 2e53cf4b5..f502bbe88 100644
--- a/src/lib/viewers/archive/__tests__/ArchiveExplorer-test-react.js
+++ b/src/lib/viewers/archive/__tests__/ArchiveExplorer-test-react.js
@@ -219,5 +219,20 @@ describe('lib/viewers/archive/ArchiveExplorer', () => {
 
             expect(sortedList[0]).to.equal(itemList[0]);
         });
+
+        it('should sort item list with null values', () => {
+            data[1].modified_at = null;
+            data[2].modified_at = null;
+
+            const component = getComponent({ filename, itemCollection: data });
+            const instance = component.instance();
+            const itemList = instance.getItemList(data, 'test/');
+
+            instance.handleSort({ sortBy: 'modified_at' });
+
+            const sortedList = instance.sortItemList(itemList);
+
+            expect(sortedList[0]).to.equal(itemList[0]);
+        });
     });
 });