diff --git a/application/libraries/Paths.php b/application/libraries/Paths.php
index 15841feaf..3afaaccc7 100644
--- a/application/libraries/Paths.php
+++ b/application/libraries/Paths.php
@@ -34,11 +34,14 @@ class Paths
 	}
 
     function cache_buster($filepath) {
+        // make sure $filepath starts with a slash
+        if (substr($filepath, 0, 1) !== '/') $filepath = '/' . $filepath;
+
         $fullpath = $_SERVER['DOCUMENT_ROOT'] . $filepath;
         if (file_exists($fullpath)) {
             return base_url($filepath) . '?v=' . filemtime($fullpath);
         } else {
-            log_message('error', 'CACHE BUSTER - File does not exist: ' . $filepath);
+            log_message('error', 'CACHE BUSTER: File does not exist: ' . $fullpath);
         }
         return base_url($filepath);
     }