diff --git a/libs/util/include/psemek/util/not_implemented.hpp b/libs/util/include/psemek/util/not_implemented.hpp
index 15a9869d..45dd01e0 100644
--- a/libs/util/include/psemek/util/not_implemented.hpp
+++ b/libs/util/include/psemek/util/not_implemented.hpp
@@ -1,8 +1,16 @@
 #pragma once
 
+#include <exception>
+
 namespace psemek::util
 {
 
-	 [[noreturn]] void not_implemented();
+	struct not_implemented_error
+		: std::exception
+	{
+		char const * what() const noexcept override;
+	};
+
+	[[noreturn]] void not_implemented();
 
 }
diff --git a/libs/util/source/not_implemented.cpp b/libs/util/source/not_implemented.cpp
index 10c39152..70515579 100644
--- a/libs/util/source/not_implemented.cpp
+++ b/libs/util/source/not_implemented.cpp
@@ -5,9 +5,14 @@
 namespace psemek::util
 {
 
+	char const * not_implemented_error::what() const noexcept
+	{
+		return "not implemented";
+	}
+
 	void not_implemented()
 	{
-		throw std::runtime_error("Not implemented");
+		throw not_implemented_error{};
 	}
 
 }