diff --git a/advagg.install b/advagg.install
index 9ac2c14..d423b7b 100644
--- a/advagg.install
+++ b/advagg.install
@@ -353,14 +353,14 @@ function advagg_check_missing_handler() {
       $url_cdn_css = advagg_build_uri($css_path . $filepath . '.css');
       $parts_css = @parse_url($url_cdn_css);
       // Do not test CDN CSS if the hosts are the same.
-      if (strcmp($parts_css['host'], $_SERVER['HTTP_HOST']) == 0) {
+      if (!empty($parts_css['host']) && strcmp($parts_css['host'], $_SERVER['HTTP_HOST']) == 0) {
         $parts_css = FALSE;
       }
 
       $url_cdn_js = advagg_build_uri($js_path . $filepath . '.js');
       $parts_js = @parse_url($url_cdn_js);
       // Do not test CDN JS if the hosts are the same.
-      if (strcmp($parts_js['host'], $_SERVER['HTTP_HOST']) == 0) {
+      if (!empty($parts_js['host']) && strcmp($parts_js['host'], $_SERVER['HTTP_HOST']) == 0) {
         $parts_js = FALSE;
       }