diff --git a/src/photo/form.ts b/src/photo/form.ts
index b9326ca0..cf4a322a 100644
--- a/src/photo/form.ts
+++ b/src/photo/form.ts
@@ -14,7 +14,7 @@ import {
 } from '@/vendors/fujifilm';
 import { FilmSimulation } from '@/simulation';
 import { GEO_PRIVACY_ENABLED } from '@/site/config';
-import { TAG_FAVS } from '@/tag';
+import { TAG_FAVS, doesTagsStringIncludeFavs } from '@/tag';
 
 type VirtualFields = 'favorite';
 
@@ -42,7 +42,7 @@ const FORM_METADATA: Record<keyof PhotoFormData, FormMeta> = {
   tags: {
     label: 'tags',
     note: 'comma-separated values',
-    validate: tags => tags?.toLowerCase().includes(TAG_FAVS)
+    validate: tags => doesTagsStringIncludeFavs(tags)
       ? `'${TAG_FAVS}' is a reserved tag`
       : undefined,
   },
diff --git a/src/tag/index.ts b/src/tag/index.ts
index 8bc7c2da..a703182f 100644
--- a/src/tag/index.ts
+++ b/src/tag/index.ts
@@ -5,7 +5,7 @@ import {
   photoQuantityText,
 } from '@/photo';
 import { absolutePathForTag, absolutePathForTagImage } from '@/site/paths';
-import { capitalizeWords } from '@/utility/string';
+import { capitalizeWords, convertStringToArray } from '@/utility/string';
 
 export const TAG_FAVS = 'favs';
 
@@ -17,6 +17,9 @@ export type Tags = {
 export const formatTag = (tag?: string) =>
   capitalizeWords(tag?.replaceAll('-', ' '));
 
+export const doesTagsStringIncludeFavs = (tags?: string) =>
+  convertStringToArray(tags)?.some(tag => isTagFavs(tag));
+
 export const titleForTag = (
   tag: string,
   photos:Photo[],