diff --git a/packages/localize/src/tools/src/extract/translation_files/format_options.ts b/packages/localize/src/tools/src/extract/translation_files/format_options.ts
index 0a3cac44430ed..43113678bb2da 100644
--- a/packages/localize/src/tools/src/extract/translation_files/format_options.ts
+++ b/packages/localize/src/tools/src/extract/translation_files/format_options.ts
@@ -7,7 +7,7 @@
  */
 
 export type FormatOptions = Record<string, string>;
-export type ValidOption = [string, string[]];
+export type ValidOption = [key: string, values: string[]];
 export type ValidOptions = ValidOption[];
 
 /**
diff --git a/packages/localize/src/tools/src/extract/translation_files/xliff1_translation_serializer.ts b/packages/localize/src/tools/src/extract/translation_files/xliff1_translation_serializer.ts
index b88107e36195e..f56a4addf214e 100644
--- a/packages/localize/src/tools/src/extract/translation_files/xliff1_translation_serializer.ts
+++ b/packages/localize/src/tools/src/extract/translation_files/xliff1_translation_serializer.ts
@@ -8,7 +8,7 @@
 import {AbsoluteFsPath, relative} from '@angular/compiler-cli/src/ngtsc/file_system';
 import {ɵParsedMessage, ɵSourceLocation} from '@angular/localize';
 
-import {validateOptions} from './format_options';
+import {FormatOptions, validateOptions} from './format_options';
 import {extractIcuPlaceholders} from './icu_parsing';
 import {TranslationSerializer} from './translation_serializer';
 import {XmlFile} from './xml_file';
@@ -25,10 +25,9 @@ const LEGACY_XLIFF_MESSAGE_LENGTH = 40;
  * @see Xliff1TranslationParser
  */
 export class Xliff1TranslationSerializer implements TranslationSerializer {
-  static validFormatOptions = new Map<string, string[]>([['xml:space', ['preserve']]]);
   constructor(
       private sourceLocale: string, private basePath: AbsoluteFsPath, private useLegacyIds: boolean,
-      private formatOptions: Record<string, string>) {
+      private formatOptions: FormatOptions) {
     validateOptions('Xliff1TranslationSerializer', [['xml:space', ['preserve']]], formatOptions);
   }
 
diff --git a/packages/localize/src/tools/src/extract/translation_files/xliff2_translation_serializer.ts b/packages/localize/src/tools/src/extract/translation_files/xliff2_translation_serializer.ts
index 1bd85513270ca..00ccd4ef6b76a 100644
--- a/packages/localize/src/tools/src/extract/translation_files/xliff2_translation_serializer.ts
+++ b/packages/localize/src/tools/src/extract/translation_files/xliff2_translation_serializer.ts
@@ -8,7 +8,7 @@
 import {AbsoluteFsPath, relative} from '@angular/compiler-cli/src/ngtsc/file_system';
 import {ɵParsedMessage, ɵSourceLocation} from '@angular/localize';
 
-import {validateOptions} from './format_options';
+import {FormatOptions, validateOptions} from './format_options';
 import {extractIcuPlaceholders} from './icu_parsing';
 import {TranslationSerializer} from './translation_serializer';
 import {XmlFile} from './xml_file';
@@ -27,7 +27,7 @@ export class Xliff2TranslationSerializer implements TranslationSerializer {
   private currentPlaceholderId = 0;
   constructor(
       private sourceLocale: string, private basePath: AbsoluteFsPath, private useLegacyIds: boolean,
-      private formatOptions: Record<string, string>) {
+      private formatOptions: FormatOptions) {
     validateOptions('Xliff1TranslationSerializer', [['xml:space', ['preserve']]], formatOptions);
   }