diff --git a/packages/client/src/components/MkPostForm.vue b/packages/client/src/components/MkPostForm.vue
index a881b670..c7b99691 100644
--- a/packages/client/src/components/MkPostForm.vue
+++ b/packages/client/src/components/MkPostForm.vue
@@ -1223,6 +1223,7 @@ onMounted(() => {
 			quoteId.value = init.renote ? init.renote.id : null;
 		}
 
+		nextTick(() => autosize.update(textareaEl.value));
 		nextTick(() => watchForDraft());
 	});
 });