diff --git a/apps/py_sems/PySemsB2ABDialog.h b/apps/py_sems/PySemsB2ABDialog.h
index af869e1c..66e36764 100644
--- a/apps/py_sems/PySemsB2ABDialog.h
+++ b/apps/py_sems/PySemsB2ABDialog.h
@@ -39,7 +39,7 @@ class PySemsB2ABDialog : public AmB2ABCallerSession,
 
   PySemsB2ABDialog();
   PySemsB2ABDialog(AmDynInvoke* user_timer);
-  ~PySemsB2ABDialog();
+  virtual ~PySemsB2ABDialog();
 
   void onSessionStart(const AmSipRequest& req);
 
@@ -65,7 +65,7 @@ class PySemsB2ABCalleeDialog : public AmB2ABCalleeSession
  PySemsB2ABCalleeDialog(const string& other_local_tag, 
 			AmSessionAudioConnector* connector)
    : AmB2ABCalleeSession(other_local_tag, connector) { }
-
+  virtual ~PySemsB2ABCalleeDialog() { }
  protected:
   void onB2ABEvent(B2ABEvent* ev);
 
diff --git a/apps/py_sems/PySemsB2BDialog.h b/apps/py_sems/PySemsB2BDialog.h
index d12ab2e5..baeb4795 100644
--- a/apps/py_sems/PySemsB2BDialog.h
+++ b/apps/py_sems/PySemsB2BDialog.h
@@ -38,7 +38,7 @@ class PySemsB2BDialog : public AmB2BCallerSession,
 
   PySemsB2BDialog();
   PySemsB2BDialog(AmDynInvoke* user_timer);
-  ~PySemsB2BDialog();
+  virtual ~PySemsB2BDialog();
 
   void onSessionStart(const AmSipRequest& req);
 
diff --git a/apps/py_sems/PySemsDialog.h b/apps/py_sems/PySemsDialog.h
index 6def6d8c..858c05e4 100644
--- a/apps/py_sems/PySemsDialog.h
+++ b/apps/py_sems/PySemsDialog.h
@@ -41,7 +41,7 @@ class PySemsDialog  :  public AmSession,
 
   PySemsDialog();
   PySemsDialog(AmDynInvoke* user_timer);
-  ~PySemsDialog();
+  virtual ~PySemsDialog();
 
   void onSessionStart(const AmSipRequest& req);