diff --git a/src/utils/ensure.hpp b/src/utils/ensure.hpp
index cbe69c5..8f266ab 100644
--- a/src/utils/ensure.hpp
+++ b/src/utils/ensure.hpp
@@ -53,6 +53,11 @@
 
     Ensure& operator=(const Ensure&) = delete;
 
+    explicit operator bool() const
+    {
+        return static_cast<bool>(functor);
+    }
+
   private:
     void clear()
     {