diff --git a/src/elog.hpp b/src/elog.hpp
index e4f5456..c3b0d02 100644
--- a/src/elog.hpp
+++ b/src/elog.hpp
@@ -30,7 +30,7 @@
             Callback() {}
 
         /** @brief Callback interface implementation. */
-        void operator()() override;
+        void operator()(Context ctx) override;
 
     private:
         /** @brief Delegate type specific calls to subclasses. */