diff --git a/lib/less/import-manager.js b/lib/less/import-manager.js
index d70c1605..386320aa 100644
--- a/lib/less/import-manager.js
+++ b/lib/less/import-manager.js
@@ -40,12 +40,14 @@ module.exports = function(environment) {
             importManager.queue.splice(importManager.queue.indexOf(path), 1); // Remove the path from the queue
 
             var importedEqualsRoot = fullPath === importManager.rootFilename;
-
+            if (importOptions.optional && e) {
+			callback(null, {rules:[]}, false, null);		
+			}
+			else {
             importManager.files[fullPath] = root;
-
             if (e && !importManager.error) { importManager.error = e; }
-
             callback(e, root, importedEqualsRoot, fullPath);
+			}
         };
 
         var newFileInfo = {