diff --git a/lib/ace/occur.js b/lib/ace/occur.js
index 9688c909..fd4fdbd9 100644
--- a/lib/ace/occur.js
+++ b/lib/ace/occur.js
@@ -80,7 +80,7 @@ oop.inherits(Occur, Search);
     }
 
     this.matchingLines = function(session, options) {
-        options = options || {};
+        options = oop.mixin({}, options);
         if (!session || !options.needle) return [];
         var search = new Search();
         search.set(options);