diff --git a/ox-rst.el b/ox-rst.el
index 7948d62..d7c8d7d 100644
--- a/ox-rst.el
+++ b/ox-rst.el
@@ -171,9 +171,9 @@ When nil, an anchor with reference is used to link to the image."
   :type 'boolean)
 
 (defcustom org-rst-inline-image-rules
-  '(("file" . "\\.\\(jpeg\\|jpg\\|png\\|webp\\|gif\\|svg\\|svgz\\|swf\\)\\'")
-    ("http" . "\\.\\(jpeg\\|jpg\\|png\\|webp\\|gif\\|svg\\|svgz\\|swf\\)\\'")
-    ("https" . "\\.\\(jpeg\\|jpg\\|png\\|webp\\|gif\\|svg\\|svgz\\|swf\\)\\'"))
+  `(("file" . ,(regexp-opt '(".jpeg" ".jpg" ".png" ".gif" ".svg" ".svgz" ".webp" ".avif")))
+    ("http" . ,(regexp-opt '(".jpeg" ".jpg" ".png" ".gif" ".svg" ".svgz" ".webp" ".avif")))
+    ("https" . ,(regexp-opt '(".jpeg" ".jpg" ".png" ".gif" ".svg" ".svgz" ".webp" ".avif"))))
   "Rules characterizing image files that can be inlined into reStructuredText.
 A rule consists in an association whose key is the type of link
 to consider, and value is a regexp that will be matched against