diff --git a/tests/unit/base/SGObjectAll_unittest.cc b/tests/unit/base/SGObjectAll_unittest.cc
index b1d02624a7f..493b8741109 100644
--- a/tests/unit/base/SGObjectAll_unittest.cc
+++ b/tests/unit/base/SGObjectAll_unittest.cc
@@ -171,7 +171,7 @@ class sg_object_iterator
 
 // list of classes that (currently) cannot be instantiated
 std::set<std::string> sg_object_all_ignores = {"ParseBuffer", "Set",
-                                               "TreeMachine", "Hierarchical"};
+                                               "TreeMachine"};
 
 // template arguments for SGObject
 // TODO: SGString doesn't support complex128_t, so omitted here