diff --git a/src/core/model/callback.h b/src/core/model/callback.h
index d0acb7bfb..76d5365a3 100644
--- a/src/core/model/callback.h
+++ b/src/core/model/callback.h
@@ -443,8 +443,6 @@ public:
   FunctorCallbackImpl (T const &functor)
     : m_functor (functor)
   {}
-  virtual ~FunctorCallbackImpl ()
-  {}
   /**
    * Functor with varying numbers of arguments
    * @{
@@ -607,8 +605,6 @@ public:
   MemPtrCallbackImpl (OBJ_PTR const&objPtr, MEM_PTR memPtr)
     : m_objPtr (objPtr), m_memPtr (memPtr)
   {}
-  virtual ~MemPtrCallbackImpl ()
-  {}
   /**
    * Functor with varying numbers of arguments
    * @{
@@ -777,8 +773,6 @@ public:
   BoundFunctorCallbackImpl (FUNCTOR functor, ARG a)
     : m_functor (functor), m_a (a)
   {}
-  virtual ~BoundFunctorCallbackImpl ()
-  {}
   /**
    * Functor with varying numbers of arguments
    * @{
@@ -935,8 +929,6 @@ public:
   TwoBoundFunctorCallbackImpl (FUNCTOR functor, ARG1 arg1, ARG2 arg2)
     : m_functor (functor), m_a1 (arg1), m_a2 (arg2)
   {}
-  virtual ~TwoBoundFunctorCallbackImpl ()
-  {}
   /**
    * Functor with varying numbers of arguments
    * @{
@@ -1083,8 +1075,6 @@ public:
   ThreeBoundFunctorCallbackImpl (FUNCTOR functor, ARG1 arg1, ARG2 arg2, ARG3 arg3)
     : m_functor (functor), m_a1 (arg1), m_a2 (arg2), m_a3 (arg3)
   {}
-  virtual ~ThreeBoundFunctorCallbackImpl ()
-  {}
   /**
    * Functor with varying numbers of arguments
    * @{
diff --git a/src/core/model/ptr.h b/src/core/model/ptr.h
index 43e1cf850..394e98a65 100644
--- a/src/core/model/ptr.h
+++ b/src/core/model/ptr.h
@@ -684,9 +684,14 @@ Ptr<T>::Ptr (T *ptr, bool ref)
 
 template <typename T>
 Ptr<T>::Ptr (Ptr const&o)
-  : m_ptr (PeekPointer (o))
+  : m_ptr (nullptr)
 {
-  Acquire ();
+  T* ptr = PeekPointer (o);
+  if (ptr != 0)
+    {
+       m_ptr = ptr;
+       Acquire ();
+    }
 }
 template <typename T>
 template <typename U>
diff --git a/src/internet/model/ipv4-l3-protocol.cc b/src/internet/model/ipv4-l3-protocol.cc
index ef45a2168..44307f0a2 100644
--- a/src/internet/model/ipv4-l3-protocol.cc
+++ b/src/internet/model/ipv4-l3-protocol.cc
@@ -1575,11 +1575,6 @@ Ipv4L3Protocol::Fragments::Fragments ()
   NS_LOG_FUNCTION (this);
 }
 
-Ipv4L3Protocol::Fragments::~Fragments ()
-{
-  NS_LOG_FUNCTION (this);
-}
-
 void
 Ipv4L3Protocol::Fragments::AddFragment (Ptr<Packet> fragment, uint16_t fragmentOffset, bool moreFragment)
 {
diff --git a/src/internet/model/ipv4-l3-protocol.h b/src/internet/model/ipv4-l3-protocol.h
index be931a604..ad4c09432 100644
--- a/src/internet/model/ipv4-l3-protocol.h
+++ b/src/internet/model/ipv4-l3-protocol.h
@@ -530,11 +530,6 @@ private:
      */
     Fragments ();
 
-    /**
-     * \brief Destructor.
-     */
-    ~Fragments ();
-
     /**
      * \brief Add a fragment.
      * \param fragment the fragment
diff --git a/src/network/utils/packetbb.cc b/src/network/utils/packetbb.cc
index 113dc46ad..37c44b36c 100644
--- a/src/network/utils/packetbb.cc
+++ b/src/network/utils/packetbb.cc
@@ -1728,11 +1728,6 @@ PbbMessageIpv4::PbbMessageIpv4 ()
   NS_LOG_FUNCTION (this);
 }
 
-PbbMessageIpv4::~PbbMessageIpv4 ()
-{
-  NS_LOG_FUNCTION (this);
-}
-
 PbbAddressLength
 PbbMessageIpv4::GetAddressLength (void) const
 {
@@ -1784,11 +1779,6 @@ PbbMessageIpv6::PbbMessageIpv6 ()
   NS_LOG_FUNCTION (this);
 }
 
-PbbMessageIpv6::~PbbMessageIpv6 ()
-{
-  NS_LOG_FUNCTION (this);
-}
-
 PbbAddressLength
 PbbMessageIpv6::GetAddressLength (void) const
 {
diff --git a/src/network/utils/packetbb.h b/src/network/utils/packetbb.h
index 2c6b96ccb..ca8fa93ee 100644
--- a/src/network/utils/packetbb.h
+++ b/src/network/utils/packetbb.h
@@ -1127,7 +1127,6 @@ private:
 class PbbMessageIpv4 : public PbbMessage {
 public:
   PbbMessageIpv4 ();
-  virtual ~PbbMessageIpv4 ();
 
 protected:
   /**
@@ -1155,7 +1154,6 @@ protected:
 class PbbMessageIpv6 : public PbbMessage {
 public:
   PbbMessageIpv6 ();
-  virtual ~PbbMessageIpv6 ();
 
 protected:
   /**
diff --git a/src/traffic-control/test/pie-queue-disc-test-suite.cc b/src/traffic-control/test/pie-queue-disc-test-suite.cc
index 52a628981..af98f2ca9 100644
--- a/src/traffic-control/test/pie-queue-disc-test-suite.cc
+++ b/src/traffic-control/test/pie-queue-disc-test-suite.cc
@@ -49,7 +49,6 @@ public:
    * \param ecnCapable ECN capable flag
    */
   PieQueueDiscTestItem (Ptr<Packet> p, const Address & addr, bool ecnCapable);
-  virtual ~PieQueueDiscTestItem ();
 
   // Delete default constructor, copy constructor and assignment operator to avoid misuse
   PieQueueDiscTestItem () = delete;
@@ -86,10 +85,6 @@ PieQueueDiscTestItem::PieQueueDiscTestItem (Ptr<Packet> p, const Address & addr,
 {
 }
 
-PieQueueDiscTestItem::~PieQueueDiscTestItem ()
-{
-}
-
 void
 PieQueueDiscTestItem::AddHeader (void)
 {
diff --git a/src/traffic-control/test/prio-queue-disc-test-suite.cc b/src/traffic-control/test/prio-queue-disc-test-suite.cc
index d6db7dcea..12cf9e0a3 100644
--- a/src/traffic-control/test/prio-queue-disc-test-suite.cc
+++ b/src/traffic-control/test/prio-queue-disc-test-suite.cc
@@ -50,7 +50,6 @@ public:
    * \param priority the packet priority
    */
   PrioQueueDiscTestItem (Ptr<Packet> p, const Address & addr, uint8_t priority);
-  virtual ~PrioQueueDiscTestItem ();
   virtual void AddHeader (void);
   virtual bool Mark (void);
 };
@@ -63,10 +62,6 @@ PrioQueueDiscTestItem::PrioQueueDiscTestItem (Ptr<Packet> p, const Address & add
   p->ReplacePacketTag (priorityTag);
 }
 
-PrioQueueDiscTestItem::~PrioQueueDiscTestItem ()
-{
-}
-
 void
 PrioQueueDiscTestItem::AddHeader (void)
 {
diff --git a/src/traffic-control/test/red-queue-disc-test-suite.cc b/src/traffic-control/test/red-queue-disc-test-suite.cc
index 3b73fa266..6b8349016 100644
--- a/src/traffic-control/test/red-queue-disc-test-suite.cc
+++ b/src/traffic-control/test/red-queue-disc-test-suite.cc
@@ -47,7 +47,6 @@ public:
    * \param ecnCapable ECN capable flag
    */
   RedQueueDiscTestItem (Ptr<Packet> p, const Address & addr, bool ecnCapable);
-  virtual ~RedQueueDiscTestItem ();
 
   // Delete default constructor, copy constructor and assignment operator to avoid misuse
   RedQueueDiscTestItem () = delete;
@@ -67,10 +66,6 @@ RedQueueDiscTestItem::RedQueueDiscTestItem (Ptr<Packet> p, const Address & addr,
 {
 }
 
-RedQueueDiscTestItem::~RedQueueDiscTestItem ()
-{
-}
-
 void
 RedQueueDiscTestItem::AddHeader (void)
 {
diff --git a/src/wave/model/default-channel-scheduler.cc b/src/wave/model/default-channel-scheduler.cc
index d81d00f1d..97156d2f3 100644
--- a/src/wave/model/default-channel-scheduler.cc
+++ b/src/wave/model/default-channel-scheduler.cc
@@ -42,9 +42,6 @@ public:
     : m_scheduler (scheduler)
   {
   }
-  virtual ~CoordinationListener ()
-  {
-  }
   virtual void NotifyCchSlotStart (Time duration)
   {
     m_scheduler->NotifyCchSlotStart (duration);