diff --git a/AMSS_NCKU_source/bssn_rhs.f90 b/AMSS_NCKU_source/bssn_rhs.f90
index 80908cb..246b219 100644
--- a/AMSS_NCKU_source/bssn_rhs.f90
+++ b/AMSS_NCKU_source/bssn_rhs.f90
@@ -106,7 +106,8 @@
   call getpbh(BHN,Porg,Mass)
 #endif
 
-!!! sanity check
+!!! sanity check (disabled in production builds for performance)
+#ifdef DEBUG
   dX = sum(chi)+sum(trK)+sum(dxx)+sum(gxy)+sum(gxz)+sum(dyy)+sum(gyz)+sum(dzz) &
       +sum(Axx)+sum(Axy)+sum(Axz)+sum(Ayy)+sum(Ayz)+sum(Azz)                   &
       +sum(Gamx)+sum(Gamy)+sum(Gamz)                                           &
@@ -136,6 +137,7 @@
      gont = 1
      return
   endif
+#endif
 
   PI = dacos(-ONE)