diff --git a/app/javascript/mastodon/features/compose/redesign/selectors.ts b/app/javascript/mastodon/features/compose/redesign/selectors.ts
index 2e217550e1b..2ccd7e83d24 100644
--- a/app/javascript/mastodon/features/compose/redesign/selectors.ts
+++ b/app/javascript/mastodon/features/compose/redesign/selectors.ts
@@ -64,7 +64,7 @@ export const selectComposeCharsCount = createAppSelector(
         : '',
   ],
   (maxChars, text, spoilerText) => {
-    const allText = (countableText(text) as string) + spoilerText;
+    const allText = countableText(text) + spoilerText;
     return {
       text,
       allText,
diff --git a/app/javascript/mastodon/features/compose/util/counter.js b/app/javascript/mastodon/features/compose/util/counter.js
deleted file mode 100644
index ec2431096b5..00000000000
--- a/app/javascript/mastodon/features/compose/util/counter.js
+++ /dev/null
@@ -1,9 +0,0 @@
-import { urlRegex } from './url_regex';
-
-const urlPlaceholder = '$2xxxxxxxxxxxxxxxxxxxxxxx';
-
-export function countableText(inputText) {
-  return inputText
-    .replace(urlRegex, urlPlaceholder)
-    .replace(/(^|[^/\w])@(([a-z0-9_]+)@[a-z0-9.-]+[a-z0-9]+)/ig, '$1@$3');
-}
diff --git a/app/javascript/mastodon/features/compose/util/counter.ts b/app/javascript/mastodon/features/compose/util/counter.ts
new file mode 100644
index 00000000000..a7449ab2dc1
--- /dev/null
+++ b/app/javascript/mastodon/features/compose/util/counter.ts
@@ -0,0 +1,9 @@
+import { urlRegex } from './url_regex';
+
+const urlPlaceholder = '$2xxxxxxxxxxxxxxxxxxxxxxx';
+
+export function countableText(inputText: string) {
+  return inputText
+    .replace(urlRegex as RegExp, urlPlaceholder)
+    .replace(/(^|[^/\w])@(([a-z0-9_]+)@[a-z0-9.-]+[a-z0-9]+)/gi, '$1@$3');
+}
diff --git a/app/javascript/mastodon/reducers/slices/composer.ts b/app/javascript/mastodon/reducers/slices/composer.ts
index 8d4f9d4c34f..a14a1652c6a 100644
--- a/app/javascript/mastodon/reducers/slices/composer.ts
+++ b/app/javascript/mastodon/reducers/slices/composer.ts
@@ -26,6 +26,7 @@ import type {
   ApiStatusJSON,
   StatusVisibility,
 } from '@/mastodon/api_types/statuses';
+import { countableText } from '@/mastodon/features/compose/util/counter';
 import {
   createAppSelector,
   createAppThunk,
@@ -269,7 +270,12 @@ export const submitComposer = createAppThunk(
 
     const maxChars =
       server.server.item?.configuration.statuses.max_characters ?? 500;
-    const textLength = length(compose.get('text') as string);
+    let text = compose.get('text') as string;
+    const spoilerText = compose.get('spoiler_text');
+    if (compose.get('spoiler') && typeof spoilerText === 'string') {
+      text += spoilerText;
+    }
+    const textLength = length(countableText(text));
     if (textLength === 0) {
       dispatch(composerSlice.actions.addError('empty'));
       return;