diff --git a/pdoc/html_helpers.py b/pdoc/html_helpers.py
index 9e213153..deac0064 100644
--- a/pdoc/html_helpers.py
+++ b/pdoc/html_helpers.py
@@ -289,7 +289,7 @@ def _admonition(match, module=None, limit_types=None):
                 '\n': ' ',
                 '[': '\\[',
                 ']': '\\]'})).strip()
-            return f'{indent}![{alt_text}]({value})\n'
+            return f'{indent}![{alt_text}]({value}){{: loading=lazy}}\n'
         if type == 'math':
             return _ToMarkdown.indent(indent,
                                       f'\\[ {text.strip()} \\]',
diff --git a/pdoc/test/__init__.py b/pdoc/test/__init__.py
index 6942b815..a48ecff0 100644
--- a/pdoc/test/__init__.py
+++ b/pdoc/test/__init__.py
@@ -1571,13 +1571,13 @@ def test_reST_directives(self):
 <div class="admonition admonition">
 <p class="admonition-title">Example</p>
 <p>Image shows something.</p>
-<p><img alt="" src="https://www.debian.org/logos/openlogo-nd-100.png"></p>
+<p><img alt="" loading="lazy" src="https://www.debian.org/logos/openlogo-nd-100.png"></p>
 <div class="admonition note">
 <p class="admonition-title">Note</p>
 <p>Can only nest admonitions two levels.</p>
 </div>
 </div>
-<p><img alt="" src="https://www.debian.org/logos/openlogo-nd-100.png"></p>
+<p><img alt="" loading="lazy" src="https://www.debian.org/logos/openlogo-nd-100.png"></p>
 <p>Now you know.</p>
 <div class="admonition warning">
 <p class="admonition-title">Warning</p>