diff --git a/src/Instrumentation/navradio.hxx b/src/Instrumentation/navradio.hxx
index 1cb7f7402..623ba784d 100644
--- a/src/Instrumentation/navradio.hxx
+++ b/src/Instrumentation/navradio.hxx
@@ -107,7 +107,6 @@ class FGNavRadio : public SGSubsystem
 
     // internal (private) values
 
-    string nav_id;
     string last_nav_id;
     bool last_nav_vor;
     int play_count;