diff --git a/polygerrit-ui/app/BUILD b/polygerrit-ui/app/BUILD
index 5f9c3c5..6eb4efe 100644
--- a/polygerrit-ui/app/BUILD
+++ b/polygerrit-ui/app/BUILD
@@ -106,7 +106,6 @@
     "elements/change/gr-reply-dialog/gr-reply-dialog_html.ts",
     "elements/change/gr-reviewer-list/gr-reviewer-list_html.ts",
     "elements/change/gr-thread-list/gr-thread-list_html.ts",
-    "elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog_html.ts",
     "elements/diff/gr-diff-builder/gr-diff-builder-element_html.ts",
     "elements/diff/gr-diff-host/gr-diff-host_html.ts",
     "elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_html.ts",
diff --git a/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog.ts b/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog.ts
index 5cd7bfc..e60c2bb 100644
--- a/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog.ts
+++ b/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog.ts
@@ -97,7 +97,7 @@
       '_computeDisableApplyFixButton(_isApplyFixLoading, change, ' +
       '_patchNum)',
   })
-  _disableApplyFixButton?: boolean;
+  _disableApplyFixButton = false;
 
   layers = appContext.flagsService.isEnabled(
     KnownExperimentId.TOKEN_HIGHLIGHTING
@@ -187,12 +187,13 @@
     return (_fixSuggestions || []).length === 1;
   }
 
-  overridePartialPrefs(prefs: DiffPreferencesInfo): DiffPreferencesInfo {
+  overridePartialPrefs(prefs?: DiffPreferencesInfo) {
+    if (!prefs) return undefined;
     // generate a smaller gr-diff than fullscreen for dialog
     return {...prefs, line_length: 50};
   }
 
-  onCancel(e: CustomEvent) {
+  onCancel(e: Event) {
     if (e) {
       e.stopPropagation();
     }
@@ -203,7 +204,7 @@
     return _selectedFixIdx + 1;
   }
 
-  _onPrevFixClick(e: CustomEvent) {
+  _onPrevFixClick(e: Event) {
     if (e) e.stopPropagation();
     if (this._selectedFixIdx >= 1 && this._fixSuggestions) {
       this._selectedFixIdx -= 1;
@@ -213,7 +214,7 @@
     }
   }
 
-  _onNextFixClick(e: CustomEvent) {
+  _onNextFixClick(e: Event) {
     if (e) e.stopPropagation();
     if (
       this._fixSuggestions &&
@@ -257,7 +258,7 @@
   }
 
   _computeDisableApplyFixButton(
-    isApplyFixLoading?: boolean,
+    isApplyFixLoading: boolean,
     change?: ParsedChangeInfo,
     patchNum?: PatchSetNum
   ) {
@@ -271,7 +272,7 @@
     return isApplyFixLoading;
   }
 
-  _handleApplyFix(e: CustomEvent) {
+  _handleApplyFix(e: Event) {
     if (e) {
       e.stopPropagation();
     }
diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.ts b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.ts
index fdde355..888e514 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.ts
@@ -40,7 +40,12 @@
 } from './gr-diff-utils';
 import {getHiddenScroll} from '../../../scripts/hiddenscroll';
 import {customElement, observe, property} from '@polymer/decorators';
-import {BlameInfo, CommentRange, ImageInfo} from '../../../types/common';
+import {
+  BlameInfo,
+  CommentRange,
+  ImageInfo,
+  NumericChangeId,
+} from '../../../types/common';
 import {
   DiffInfo,
   DiffPreferencesInfo,
@@ -155,7 +160,7 @@
    */
 
   @property({type: String})
-  changeNum?: string;
+  changeNum?: NumericChangeId;
 
   @property({type: Boolean})
   noAutoRender = false;