diff --git a/src/util/hei_flyweight.hpp b/src/util/hei_flyweight.hpp
index 6228759..a81fe30 100644
--- a/src/util/hei_flyweight.hpp
+++ b/src/util/hei_flyweight.hpp
@@ -18,7 +18,10 @@
     Flyweight() = default;
 
     /** @brief Destructor. */
-    ~Flyweight() = default;
+    ~Flyweight()
+    {
+        clear();
+    }
 
     /** @brief Default copy constructor. */
     Flyweight(const Flyweight&) = delete;