diff --git a/toonz/sources/include/toonz/ttileset.h b/toonz/sources/include/toonz/ttileset.h
index 450c5d9..e5dfac9 100644
--- a/toonz/sources/include/toonz/ttileset.h
+++ b/toonz/sources/include/toonz/ttileset.h
@@ -51,7 +51,7 @@ protected:
 
 public:
   TTileSet(const TDimension &dim) : m_srcImageSize(dim) {}
-  ~TTileSet();
+  virtual ~TTileSet();
 
   int getMemorySize() const;