diff --git a/templates/utils.html b/templates/utils.html
index fce8184..b0bf6d9 100644
--- a/templates/utils.html
+++ b/templates/utils.html
@@ -245,7 +245,7 @@
 	<h3 class="l">Attachments</h3>
 	<ul style="padding:0;list-style-type: none;">
 	{% endif %}
-	{% for a in obj.attachment %}
+	{% for a in (obj | iter_note_attachments) %}
     {% if (a.mediaType and a.mediaType.startswith("image/")) or (a.type and a.type == 'Image') %}
     <a href="{{ a.url | get_attachment_url(None) }}">
         <img src="{{a.url | get_attachment_url(720) }}" title="{{ a.name }}" alt="{{ a.name }}" class="img-attachment"></a>
diff --git a/utils/template_filters.py b/utils/template_filters.py
index 4220cb5..f3c225b 100644
--- a/utils/template_filters.py
+++ b/utils/template_filters.py
@@ -2,6 +2,7 @@ import logging
 import urllib
 from datetime import datetime
 from datetime import timezone
+from functools import lru_cache
 from urllib.parse import urlparse
 
 import bleach
@@ -345,6 +346,7 @@ def get_attachment_url(url, size):
 
 
 @filters.app_template_filter()
+@lru_cache(maxsize=256)
 def update_inline_imgs(content):
     soup = BeautifulSoup(content, "html5lib")
     imgs = soup.find_all("img")
@@ -418,6 +420,28 @@ def has_actor_type(doc):
     return False
 
 
+@lru_cache(maxsize=256)
+def _get_inlined_imgs(content):
+    imgs = []
+    if not content:
+        return imgs
+
+    soup = BeautifulSoup(content, "html5lib")
+    for img in soup.find_all("img"):
+        src = img.attrs.get("src")
+        if src:
+            imgs.append(src)
+
+    return imgs
+
+
+@filters.app_template_filter()
+def iter_note_attachments(note):
+    attachments = note.get("attachment", [])
+    imgs = _get_inlined_imgs(note.get("content"))
+    return [a for a in attachments if a.get("url") not in imgs]
+
+
 @filters.app_template_filter()
 def not_only_imgs(attachment):
     for a in attachment: