diff --git a/util/test/rdtest/testcase.py b/util/test/rdtest/testcase.py
index aef91b541..e9eeb45d1 100644
--- a/util/test/rdtest/testcase.py
+++ b/util/test/rdtest/testcase.py
@@ -205,7 +205,7 @@ class TestCase:
                     raise TestFailureException('PostVS data[{}] doesn\'t contain data {} as expected. Data is: {}'.format(idx, key, list(data.keys())))
 
                 if not util.value_compare(ref[key], data[key]):
-                    raise TestFailureException('PostVS data \'{}\': {} is not as expected: {}'.format(key, data[key], ref[key]))
+                    raise TestFailureException('PostVS data[{}] \'{}\': {} is not as expected: {}'.format(idx, key, data[key], ref[key]))
 
         log.success("Mesh data is identical to reference")