diff --git a/compiler/tests/org/jetbrains/jet/test/util/NamespaceComparator.java b/compiler/tests/org/jetbrains/jet/test/util/NamespaceComparator.java
index 96435ae1283..6e74d564f03 100644
--- a/compiler/tests/org/jetbrains/jet/test/util/NamespaceComparator.java
+++ b/compiler/tests/org/jetbrains/jet/test/util/NamespaceComparator.java
@@ -108,7 +108,7 @@ public class NamespaceComparator {
 
         sb.append("namespace " + nsa.getName() + "\n\n");
 
-        deferred.assertTrue(!nsa.getMemberScope().getAllDescriptors().isEmpty());
+        deferred.assertTrue("namespace " + nsa.getName() + " is empty", !nsa.getMemberScope().getAllDescriptors().isEmpty());
 
         Set<Name> classifierNames = new HashSet<Name>();
         Set<Name> propertyNames = new HashSet<Name>();