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()} \\]',