diff --git a/AMSS_NCKU_Input.py b/AMSS_NCKU_Input.py
index 73af547..688f663 100755
--- a/AMSS_NCKU_Input.py
+++ b/AMSS_NCKU_Input.py
@@ -158,7 +158,7 @@ Detector_Rmax   = 160.0                  ## farest dector distance
 
 ## Setting the apprent horizon
 
-AHF_Find       = "no"                    ## whether to find the apparent horizon: choose "yes" or "no"
+AHF_Find       = "yes"                    ## whether to find the apparent horizon: choose "yes" or "no"
 
 AHF_Find_Every = 24
 AHF_Dump_Time  = 20.0
diff --git a/AMSS_NCKU_source/bssn_class.C b/AMSS_NCKU_source/bssn_class.C
index 3dc56e4..3a53e9c 100644
--- a/AMSS_NCKU_source/bssn_class.C
+++ b/AMSS_NCKU_source/bssn_class.C
@@ -9402,9 +9402,16 @@ void bssn_class::AH_Step_Find(int lev, double dT_lev)
         xr[ihn] = yr[ihn] = zr[ihn] = 50;
         //	if(myrank==0) for(ihn=0;ihn<HN_num;ihn++) cout<<"trigger#"<<ihn<<": "<<trigger[ihn]<<endl;
       }
+#endif
+#if USE_CUDA_BSSN
+      if (bssn_cuda_use_resident_sync(lev))
+      {
+        for (int dl = 0; dl < GH->levels; dl++)
+          bssn_cuda_download_level_state_if_present(GH->PatL[dl], StateList, myrank);
+      }
 #endif
       AHFinderDirect::AHFinderDirect_find_horizons(HN_num, dumpid,
-                                                   xc, yc, zc, xr, yr, zr, trigger, dTT); 
+                                                   xc, yc, zc, xr, yr, zr, trigger, dTT);
       // note rhs and Gamijk have been used as temp storage space
 
       if (myrank == 0)