diff --git a/hwmon.hpp b/hwmon.hpp
index c822045..a19aa34 100644
--- a/hwmon.hpp
+++ b/hwmon.hpp
@@ -9,6 +9,7 @@
 namespace entry
 {
 static const std::string input = "input"s;
+static const std::string label = "label"s;
 }
 
 namespace type