diff --git a/src/backend/concrete_history.cc b/src/backend/concrete_history.cc
index 8d2e85b..db21e73 100644
--- a/src/backend/concrete_history.cc
+++ b/src/backend/concrete_history.cc
@@ -293,11 +293,10 @@ ConcreteHistory::remove(SubRequest& subrequest)
 void
 ConcreteHistory::clear()
 {
-  for_each(_snapshots.begin(), _snapshots.end(),
-           deletor<ConcreteEnvironment>());
-  _snapshots.clear();
-  _snapshots.push_back(new ConcreteEnvironment());
+  reset(false);
   assert(_snapshots.size() == 1);
+  delete _snapshots.front();
+  _snapshots.front() = new ConcreteEnvironment();
   notify_change();
 }
 
@@ -400,7 +399,6 @@ ConcreteHistory::add_thread(const Glib::ustring& name,
 {
   reset(false);
 
-  // Holy cow! *THIS* is ugly!!!!
   DynamicProcess& parent_process = dynamic_cast<DynamicProcess&>(parent);
   StaticProcess&  parent_core    = parent_process.get_core();
   StaticThread*   core   = new StaticThread(name, parent_core, cpu_time, arrival_time, base_priority);