--- a/testing/mochitest/chunkifyTests.js
+++ b/testing/mochitest/chunkifyTests.js
@@ -66,17 +66,22 @@ function chunkifyTests(tests, totalChunk
   }
 
   return returnTests;
 }
 
 function skipTests(tests, startTestPattern, endTestPattern) {
   var startIndex = 0, endIndex = tests.length - 1;
   for (var i = 0; i < tests.length; ++i) {
-    var test_path = tests[i];
+    var test_path;
+    if ((tests[i] instanceof Object) && ('test' in tests[i])) {
+      test_path = tests[i]['test']['url'];
+    } else {
+      test_path = tests[i];
+    }
     if (startTestPattern && test_path.endsWith(startTestPattern)) {
       startIndex = i;
     }
 
     if (endTestPattern && test_path.endsWith(endTestPattern)) {
       endIndex = i;
     }
   }