diff --git a/intl/lwbrk/public/nsIBreakState.h b/intl/lwbrk/public/nsIBreakState.h
index 72ce38924afa..0634d711537e 100644
--- a/intl/lwbrk/public/nsIBreakState.h
+++ b/intl/lwbrk/public/nsIBreakState.h
@@ -52,7 +52,7 @@ class name : public nsIBreakState {                          \
      mText = aText; mLen = aLen;                             \
      mPos = 0; mPriv = 0; mDone = PR_FALSE;                  \
   } ;                                                        \
-  ~name () { }  ;                                            \
+  virtual ~name () { }  ;                                    \
                                                              \
 public:                                                      \
   NS_IMETHOD Set (PRUint32 aPos, PRBool aDone)               \
diff --git a/intl/lwbrk/src/nsJISx4501LineBreaker.h b/intl/lwbrk/src/nsJISx4501LineBreaker.h
index 08a00c2c7bad..66cb1f949fc0 100644
--- a/intl/lwbrk/src/nsJISx4501LineBreaker.h
+++ b/intl/lwbrk/src/nsJISx4501LineBreaker.h
@@ -28,7 +28,7 @@ class nsJISx4501LineBreaker : public nsILineBreaker
 public:
   nsJISx4501LineBreaker(const PRUnichar *aNoBegin, PRInt32 aNoBeginLen, 
                         const PRUnichar* aNoEnd, PRInt32 aNoEndLen);
-  ~nsJISx4501LineBreaker();
+  virtual ~nsJISx4501LineBreaker();
 
   NS_IMETHOD BreakInBetween(const PRUnichar* aText1 , PRUint32 aTextLen1,
                             const PRUnichar* aText2 , PRUint32 aTextLen2,
diff --git a/intl/lwbrk/src/nsLWBreakerFImp.h b/intl/lwbrk/src/nsLWBreakerFImp.h
index 652bc05cfc90..ef44681d57c1 100644
--- a/intl/lwbrk/src/nsLWBreakerFImp.h
+++ b/intl/lwbrk/src/nsLWBreakerFImp.h
@@ -35,7 +35,7 @@ class nsLWBreakerFImp : public nsILineBreakerFactory , nsIWordBreakerFactory
 public:
   
   nsLWBreakerFImp();
-  ~nsLWBreakerFImp();
+  virtual ~nsLWBreakerFImp();
   
   NS_IMETHOD GetBreaker(nsString& aParam, nsILineBreaker** breaker);
   NS_IMETHOD GetBreaker(nsString& aParam, nsIWordBreaker** breaker);
diff --git a/intl/lwbrk/src/nsLWBrk.cpp b/intl/lwbrk/src/nsLWBrk.cpp
index f81b04066374..3be6284165f9 100644
--- a/intl/lwbrk/src/nsLWBrk.cpp
+++ b/intl/lwbrk/src/nsLWBrk.cpp
@@ -39,7 +39,7 @@ class nsLWBrkFactory : public nsIFactory {
     NS_INIT_REFCNT();
     PR_AtomicIncrement(&g_InstanceCount);
   };
-  ~nsLWBrkFactory() {
+  virtual ~nsLWBrkFactory() {
     PR_AtomicDecrement(&g_InstanceCount);
   };
 
diff --git a/intl/lwbrk/src/nsSampleWordBreaker.h b/intl/lwbrk/src/nsSampleWordBreaker.h
index cc1d65dd74de..f13720c321cf 100644
--- a/intl/lwbrk/src/nsSampleWordBreaker.h
+++ b/intl/lwbrk/src/nsSampleWordBreaker.h
@@ -27,7 +27,7 @@ class nsSampleWordBreaker : public nsIWordBreaker
 public:
 
   nsSampleWordBreaker() ;
-  ~nsSampleWordBreaker() ;
+  virtual ~nsSampleWordBreaker() ;
 
   NS_IMETHOD BreakInBetween(const PRUnichar* aText1 , PRUint32 aTextLen1,
                             const PRUnichar* aText2 , PRUint32 aTextLen2,