diff --git a/javascripts/discourse/initializers/disco-toc-composer.js b/javascripts/discourse/initializers/disco-toc-composer.js
index 1ae3789..6305d12 100644
--- a/javascripts/discourse/initializers/disco-toc-composer.js
+++ b/javascripts/discourse/initializers/disco-toc-composer.js
@@ -38,7 +38,7 @@ export default {
             action: "insertDtoc",
             icon: "align-left",
             label: themePrefix("insert_table_of_contents"),
-            condition: controller.get("model.creatingTopic"),
+            condition: controller.get("model.topicFirstPost"),
           };
         });
       }
diff --git a/test/acceptance/toc-composer-test.js b/test/acceptance/toc-composer-test.js
index 65683da..9d734ac 100644
--- a/test/acceptance/toc-composer-test.js
+++ b/test/acceptance/toc-composer-test.js
@@ -1,4 +1,8 @@
-import { acceptance, query } from "discourse/tests/helpers/qunit-helpers";
+import {
+  acceptance,
+  exists,
+  query,
+} from "discourse/tests/helpers/qunit-helpers";
 import { click, visit } from "@ember/test-helpers";
 import selectKit from "discourse/tests/helpers/select-kit-helper";
 import { test } from "qunit";
@@ -16,6 +20,20 @@ acceptance("DiscoTOC - Composer", function (needs) {
     assert.ok(query(".d-editor-input").value.includes('data-theme-toc="true"'));
   });
 
+  test("Can use TOC when editing first post", async function (assert) {
+    await visit("/t/internationalization-localization/280");
+    await click("#post_1 .show-more-actions");
+    await click("#post_1 .edit");
+
+    assert.ok(exists("#reply-control"));
+
+    const toolbarPopupMenu = selectKit(".toolbar-popup-menu-options");
+    await toolbarPopupMenu.expand();
+    await toolbarPopupMenu.selectRowByValue("insertDtoc");
+
+    assert.ok(query(".d-editor-input").value.includes('data-theme-toc="true"'));
+  });
+
   test("no TOC option when replying", async function (assert) {
     await visit("/t/internationalization-localization/280");
     await click(".create.reply");