diff --git a/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list.ts b/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list.ts
index 108f9ed..7759b7b 100644
--- a/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list.ts
+++ b/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list.ts
@@ -1558,7 +1558,7 @@
             'changeComments, patchRange and diffPrefs must be set'
           );
         }
-        diffElem.comments = this.changeComments.getCommentsBySideForFile(
+        diffElem.threads = this.changeComments.getThreadsBySideForFile(
           file,
           this.patchRange,
           this.projectConfig
diff --git a/polygerrit-ui/app/elements/diff/gr-comment-api/gr-comment-api.ts b/polygerrit-ui/app/elements/diff/gr-comment-api/gr-comment-api.ts
index b01a110..683d887 100644
--- a/polygerrit-ui/app/elements/diff/gr-comment-api/gr-comment-api.ts
+++ b/polygerrit-ui/app/elements/diff/gr-comment-api/gr-comment-api.ts
@@ -38,7 +38,7 @@
   RevisionId,
 } from '../../../types/common';
 import {hasOwnProperty} from '../../../utils/common-util';
-import {CommentSide} from '../../../constants/constants';
+import {CommentSide, Side} from '../../../constants/constants';
 import {RestApiService} from '../../../services/services/gr-rest-api/gr-rest-api';
 import {
   Comment,
@@ -313,6 +313,30 @@
     return allDrafts;
   }
 
+  _addCommentSide(comments: TwoSidesComments) {
+    const allComments = [];
+    for (const side of [Side.LEFT, Side.RIGHT]) {
+      // This is needed by the threading.
+      for (const comment of comments[side]) {
+        comment.__commentSide = side;
+      }
+      allComments.push(...comments[side]);
+    }
+    return allComments;
+  }
+
+  getThreadsBySideForPath(
+    path: string,
+    patchRange: PatchRange,
+    projectConfig?: ConfigInfo
+  ): CommentThread[] {
+    return createCommentThreads(
+      this._addCommentSide(
+        this.getCommentsBySideForPath(path, patchRange, projectConfig)
+      )
+    );
+  }
+
   /**
    * Get the comments (with drafts and robot comments) for a path and
    * patch-range. Returns an object with left and right properties mapping to
@@ -371,6 +395,18 @@
     };
   }
 
+  getThreadsBySideForFile(
+    file: PatchSetFile,
+    patchRange: PatchRange,
+    projectConfig?: ConfigInfo
+  ): CommentThread[] {
+    return createCommentThreads(
+      this._addCommentSide(
+        this.getCommentsBySideForFile(file, patchRange, projectConfig)
+      )
+    );
+  }
+
   /**
    * Get the comments (with drafts and robot comments) for a file and
    * patch-range. Returns an object with left and right properties mapping to
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host.ts b/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host.ts
index aa769c6..4b4f429 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host.ts
@@ -31,8 +31,7 @@
   isMergeParent,
   isNumber,
 } from '../../../utils/patch-set-util';
-import {CommentThread, createCommentThreads} from '../../../utils/comment-util';
-import {TwoSidesComments} from '../gr-comment-api/gr-comment-api';
+import {CommentThread} from '../../../utils/comment-util';
 import {customElement, observe, property} from '@polymer/decorators';
 import {
   CommitRange,
@@ -192,8 +191,8 @@
   @property({type: Boolean})
   noRenderOnPrefsChange = false;
 
-  @property({type: Object, observer: '_commentsChanged'})
-  comments?: TwoSidesComments;
+  @property({type: Object, observer: '_threadsChanged'})
+  threads?: CommentThread[];
 
   @property({type: Boolean})
   lineWrapping = false;
@@ -674,21 +673,12 @@
     return isImageDiff(diff);
   }
 
-  _commentsChanged(newComments: TwoSidesComments) {
-    const allComments = [];
-    for (const side of [Side.LEFT, Side.RIGHT]) {
-      // This is needed by the threading.
-      for (const comment of newComments[side]) {
-        comment.__commentSide = side;
-      }
-      allComments.push(...newComments[side]);
-    }
+  _threadsChanged(threads: CommentThread[]) {
     // Currently, the only way this is ever changed here is when the initial
-    // comments are loaded, so it's okay performance wise to clear the threads
+    // threads are loaded, so it's okay performance wise to clear the threads
     // and recreate them. If this changes in future, we might want to reuse
     // some DOM nodes here.
     this._clearThreads();
-    const threads = createCommentThreads(allComments);
     for (const thread of threads) {
       const threadEl = this._createThreadElement(thread);
       this._attachThreadElement(threadEl);
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.ts b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.ts
index c169bf4..bb0ed61 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.ts
@@ -65,11 +65,7 @@
   GrDropdownList,
 } from '../../shared/gr-dropdown-list/gr-dropdown-list';
 import {GrOverlay} from '../../shared/gr-overlay/gr-overlay';
-import {
-  ChangeComments,
-  GrCommentApi,
-  TwoSidesComments,
-} from '../gr-comment-api/gr-comment-api';
+import {ChangeComments, GrCommentApi} from '../gr-comment-api/gr-comment-api';
 import {GrDiffModeSelector} from '../gr-diff-mode-selector/gr-diff-mode-selector';
 import {
   ChangeInfo,
@@ -240,9 +236,6 @@
   @property({type: Object})
   _commentMap?: CommentMap;
 
-  @property({type: Object})
-  _commentsForDiff?: TwoSidesComments;
-
   @property({
     type: Object,
     computed: '_computeCommentSkips(_commentMap, _fileList, _path)',
@@ -1013,12 +1006,6 @@
     }
 
     this._commentMap = this._getPaths(this._patchRange);
-
-    this._commentsForDiff = this._getCommentsForPath(
-      this._path,
-      this._patchRange,
-      this._projectConfig
-    );
   }
 
   _isFileUnchanged(diff: DiffInfo) {
@@ -1087,7 +1074,13 @@
         this._loading = false;
         this._initPatchRange();
         this._initCommitRange();
-        this.$.diffHost.comments = this._commentsForDiff;
+        if (this._changeComments && this._path && this._patchRange) {
+          this.$.diffHost.threads = this._changeComments.getThreadsBySideForPath(
+            this._path,
+            this._patchRange,
+            this._projectConfig
+          );
+        }
         portedCommentsPromise.then(() => {
           this.reporting.timeEnd(PORTING_COMMENTS_DIFF_LATENCY_LABEL);
         });
@@ -1575,13 +1568,11 @@
 
     const file = files[path];
     if (file && file.old_path) {
-      this._commentsForDiff = this._changeComments.getCommentsBySideForFile(
+      this.$.diffHost.threads = this._changeComments.getThreadsBySideForFile(
         {path, basePath: file.old_path},
         patchRange,
         projectConfig
       );
-
-      this.$.diffHost.comments = this._commentsForDiff;
     }
   }
 
@@ -1590,22 +1581,6 @@
     return this._changeComments.getPaths(patchRange);
   }
 
-  _getCommentsForPath(
-    path?: string,
-    patchRange?: PatchRange,
-    projectConfig?: ConfigInfo
-  ) {
-    if (!path) return undefined;
-    if (!patchRange) return undefined;
-    if (!this._changeComments) return undefined;
-
-    return this._changeComments.getCommentsBySideForPath(
-      path,
-      patchRange,
-      projectConfig
-    );
-  }
-
   _getDiffDrafts() {
     if (!this._changeNum) throw new Error('Missing this._changeNum');
 
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.js b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.js
index 7ef75ed..8e1e5c1 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.js
@@ -151,8 +151,10 @@
         computeCommentThreadCount: () => {},
         computeUnresolvedNum: () => {},
         getPaths: () => {},
-        getCommentsBySideForPath: () => {},
+        getThreadsBySideForPath: () => {},
+        getThreadsBySideForFile: () => {},
         findCommentById: _testOnly_findCommentById,
+
       }));
       await element._loadComments();
       await flush();
@@ -200,11 +202,6 @@
         commentLink: true,
         commentId: 'c1',
       };
-      sinon.stub(element.$.diffHost, '_commentsChanged');
-      sinon.stub(element, '_getCommentsForPath').returns({
-        left: [{id: 'c1', __commentSide: 'left', line: 10}],
-        right: [{id: 'c2', __commentSide: 'right', line: 11}],
-      });
       element._change = {
         ...createChange(),
         revisions: createRevisions(11),
@@ -263,7 +260,6 @@
             commentLink: true,
             commentId: 'c1',
           };
-          sinon.stub(element.$.diffHost, '_commentsChanged');
           element._change = {
             ...createChange(),
             revisions: createRevisions(11),
@@ -293,7 +289,6 @@
             commentLink: true,
             commentId: 'c3',
           };
-          sinon.stub(element.$.diffHost, '_commentsChanged');
           element._change = {
             ...createChange(),
             revisions: createRevisions(11),
@@ -1455,7 +1450,6 @@
         await flush();
       });
       test('empty', () => {
-        sinon.stub(element, '_getCommentsForPath');
         sinon.stub(element, '_getPaths').returns(new Map());
         element._initPatchRange();
         assert.equal(Object.keys(element._commentMap).length, 0);
@@ -1467,7 +1461,6 @@
           'path/to/file/one.cpp': [{patch_set: 3, message: 'lorem'}],
           'path-to/file/two.py': [{patch_set: 5, message: 'ipsum'}],
         });
-        sinon.stub(element, '_getCommentsForPath').returns({meta: {}});
         element._changeNum = '42';
         element._patchRange = {
           basePatchNum: 3,