diff --git a/src/lib/dns/tsigkey.h b/src/lib/dns/tsigkey.h
index 1380319c5f..ead33e1463 100644
--- a/src/lib/dns/tsigkey.h
+++ b/src/lib/dns/tsigkey.h
@@ -154,7 +154,7 @@ public:
     TSIGKey& operator=(const TSIGKey& source);
 
     /// The destructor.
-    ~TSIGKey();
+    virtual ~TSIGKey();
     //@}
 
     ///