diff --git a/min/lib/Minify/CSS/UriRewriter.php b/min/lib/Minify/CSS/UriRewriter.php
index 56f3424..af3bbd4 100644
--- a/min/lib/Minify/CSS/UriRewriter.php
+++ b/min/lib/Minify/CSS/UriRewriter.php
@@ -284,7 +284,7 @@ class Minify_CSS_UriRewriter {
         }
         // analyze URI
         if ('/' !== $uri[0]                  // root-relative
-            && !preg_match('~about\:blank(#.*)?$~', $uri) //about:blank
+            && !preg_match('~^about\:blank(#.*)?$~', $uri) //about:blank
             && false === strpos($uri, '//')  // protocol (non-data)
             && 0 !== strpos($uri, 'data:')   // data protocol
         ) {