diff --git a/src/js/lib.js b/src/js/lib.js
index f0df779..23196b7 100644
--- a/src/js/lib.js
+++ b/src/js/lib.js
@@ -48,8 +48,12 @@ const getDiffElement = (fileId) => {
     return el
   }
 
-  const gitHubEnterpriseEl = document.querySelector(`[data-anchor="${fileId}"]`).parentElement
-  return gitHubEnterpriseEl
+  const gitHubEnterpriseEl = document.querySelector(`[data-anchor="${fileId}"]`)
+  if (gitHubEnterpriseEl) {
+    return gitHubEnterpriseEl.parentElement
+  }
+
+  return null
 }
 
 const countCommentsForFileId = (fileId) => {
@@ -115,6 +119,7 @@ export const createFileTree = (filter = EMPTY_FILTER) => {
     title = getCurrentFileLocation(title)
     return { title, href, parts: title.split('/') }
   })
+  const count = fileInfo.filter(({ href }) => href && href.includes('#diff')).length
   const tree = {
     nodeLabel: '/',
     list: [],
@@ -129,20 +134,22 @@ export const createFileTree = (filter = EMPTY_FILTER) => {
         if (!node) {
           const hrefSplit = href.split('#')
           const fileId = hrefSplit[hrefSplit.length - 1]
-          const hasComments = (countCommentsForFileId(fileId) > 0)
-          const isDeleted = isDeletedForFileId(fileId)
           const diffElement = getDiffElement(fileId)
-          tree.diffElements.push(diffElement)
-          node = {
-            nodeLabel: part,
-            list: [],
-            href: (index === parts.length - 1) ? href : null,
-            hasComments,
-            isDeleted,
-            diffElement,
-            diffStats: getDiffStatsForDiffElement(diffElement)
+          if (diffElement) {
+            const hasComments = (countCommentsForFileId(fileId) > 0)
+            const isDeleted = isDeletedForFileId(fileId)
+            tree.diffElements.push(diffElement)
+            node = {
+              nodeLabel: part,
+              list: [],
+              href: (index === parts.length - 1) ? href : null,
+              hasComments,
+              isDeleted,
+              diffElement,
+              diffStats: getDiffStatsForDiffElement(diffElement)
+            }
+            location.list.push(node)
           }
-          location.list.push(node)
         }
         location.list = location.list.sort(sorter)
         location = node
@@ -151,7 +158,7 @@ export const createFileTree = (filter = EMPTY_FILTER) => {
   })
   return {
     tree: folderConcat(tree),
-    count: fileInfo.length
+    count
   }
 }
 
@@ -177,9 +184,9 @@ const EMPTY_FILTER = ''
 
 export const getBrowserApi = () => {
   let browserApi = window.chrome
-    if (typeof browser !== 'undefined') {
-      browserApi = browser
-    }
+  if (typeof browser !== 'undefined') {
+    browserApi = browser
+  }
   return browserApi
 }