diff --git a/dbus/dbusutil.cpp b/dbus/dbusutil.cpp
index fc67439..b80dff8 100644
--- a/dbus/dbusutil.cpp
+++ b/dbus/dbusutil.cpp
@@ -52,6 +52,7 @@
     {
         return;
     }
+    value -= min;
     value /= (max - min);
 }