diff --git a/plugins/af_zz_imgproxy/init.php b/plugins/af_zz_imgproxy/init.php
index 9ef813ce8..2102370e3 100644
--- a/plugins/af_zz_imgproxy/init.php
+++ b/plugins/af_zz_imgproxy/init.php
@@ -24,7 +24,7 @@ class Af_Zz_ImgProxy extends Plugin {
 	}
 
 	function hook_enclosure_entry($enc) {
-		if (preg_match("/image/", $enc["type"]) || preg_match("/\.(jpg|png|gif|bmp)/i", $enc["filename"])) {
+		if (preg_match("/image/", $enc["content_type"]) || preg_match("/\.(jpe?g|png|gif|bmp)$/i", $enc["filename"])) {
 			$proxy_all = $this->host->get($this, "proxy_all");
 
 			$enc["content_url"] = $this->rewrite_url_if_needed($enc["content_url"], $proxy_all);