diff --git a/tests/auto/cplusplus/lookup/tst_lookup.cpp b/tests/auto/cplusplus/lookup/tst_lookup.cpp
index ecf3ae71fef..38d193faf64 100644
--- a/tests/auto/cplusplus/lookup/tst_lookup.cpp
+++ b/tests/auto/cplusplus/lookup/tst_lookup.cpp
@@ -12,6 +12,17 @@
 
 CPLUSPLUS_USE_NAMESPACE
 
+template <template <typename, typename> class _Map, typename _T1, typename _T2>
+_Map<_T2, _T1> invert(const _Map<_T1, _T2> &m)
+{
+    _Map<_T2, _T1> i;
+    typename _Map<_T1, _T2>::const_iterator it = m.constBegin();
+    for (; it != m.constEnd(); ++it) {
+        i.insertMulti(it.value(), it.key());
+    }
+    return i;
+}
+
 class ClassSymbols: protected ASTVisitor,
     public QMap<ClassSpecifierAST *, Class *>
 {
@@ -20,6 +31,9 @@ public:
         : ASTVisitor(control)
     { }
 
+    QMap<ClassSpecifierAST *, Class *> asMap() const
+    { return *this; }
+
     void operator()(AST *ast)
     { accept(ast); }
 
@@ -62,7 +76,7 @@ void tst_Lookup::base_class_defined_1()
     Snapshot snapshot;
     snapshot.insert(doc->fileName(), doc);
 
-    Document::Ptr emptyDoc = Document::create("empty");
+    Document::Ptr emptyDoc = Document::create("<empty>");
 
     Class *baseClass = doc->globalSymbolAt(0)->asClass();
     QVERIFY(baseClass);
@@ -88,6 +102,12 @@ void tst_Lookup::base_class_defined_1()
     classSymbols(ast);
 
     QCOMPARE(classSymbols.size(), 2);
+
+    const QMap<Class *, ClassSpecifierAST *> classToAST =
+            invert(classSymbols.asMap());
+
+    QVERIFY(classToAST.value(baseClass) != 0);
+    QVERIFY(classToAST.value(derivedClass) != 0);
 }
 
 QTEST_APPLESS_MAIN(tst_Lookup)