diff --git a/urandom_entropy_src.h b/urandom_entropy_src.h
index 722e786..9d63c8b 100644
--- a/urandom_entropy_src.h
+++ b/urandom_entropy_src.h
@@ -36,6 +36,8 @@ public:
 		}
 	}
 
+	auto urandom_entropy_src_service() -> int;
+
 private:
 	static std::vector<char> bytes[max_event_length];
 };