diff --git a/src/wifi/model/qos-txop.h b/src/wifi/model/qos-txop.h
index 797cf9a69..6e9efe671 100644
--- a/src/wifi/model/qos-txop.h
+++ b/src/wifi/model/qos-txop.h
@@ -437,13 +437,15 @@ public:
    */
   Mac48Address MapDestAddressForAggregation (const WifiMacHeader &hdr);
 
+protected:
+  // Overridden from Txop
+  void DoDispose (void);
 
 private:
   /// allow AggregationCapableTransmissionListener class access
   friend class AggregationCapableTransmissionListener;
 
   // Overridden from Txop
-  void DoDispose (void);
   void DoInitialize (void);
   void TerminateTxop (void);
   uint32_t GetNextFragmentSize (void) const;
diff --git a/src/wifi/test/channel-access-manager-test.cc b/src/wifi/test/channel-access-manager-test.cc
index 019b23588..40309bdd1 100644
--- a/src/wifi/test/channel-access-manager-test.cc
+++ b/src/wifi/test/channel-access-manager-test.cc
@@ -426,7 +426,7 @@ void
 TxopTest<TxopType>::DoDispose (void)
 {
   m_test = 0;
-  Txop::DoDispose ();
+  TxopType::DoDispose ();
 }
 
 template <typename TxopType>
@@ -620,7 +620,6 @@ void
 ChannelAccessManagerTest<TxopType>::EndTest (void)
 {
   Simulator::Run ();
-  Simulator::Destroy ();
 
   for (typename TxopTests::const_iterator i = m_txop.begin (); i != m_txop.end (); i++)
     {
@@ -633,9 +632,11 @@ ChannelAccessManagerTest<TxopType>::EndTest (void)
     }
   m_txop.clear ();
 
+  m_ChannelAccessManager->Dispose ();
   m_ChannelAccessManager = 0;
   m_low = 0;
   m_feManager = 0;
+  Simulator::Destroy ();
 }
 
 template <typename TxopType>