diff --git a/tracy/tracy/inc/tracy_global.h b/tracy/tracy/inc/tracy_global.h
index 889a867cc84179fc4f2a7ac327c5b23c31053969..e9319133b24d17005a0578e800c723a1cc4ae9cf 100644
--- a/tracy/tracy/inc/tracy_global.h
+++ b/tracy/tracy/inc/tracy_global.h
@@ -25,6 +25,7 @@ typedef struct globvalrec {
   long int       qt;           // family index of skew quadrupole
   int            gs;             // family number of start girder  
   int            ge;             // family number of end girder 
+  long int         cav;          // family index of RF cavity
   
   // matrix
   Matrix        OneTurnMat,     // oneturn matrix