diff --git a/Regression/Checksum/benchmarks_json/test_2d_rigid_injection_btd.json b/Regression/Checksum/benchmarks_json/test_2d_rigid_injection_btd.json
index 90cf134201f..9e876d5c23e 100644
--- a/Regression/Checksum/benchmarks_json/test_2d_rigid_injection_btd.json
+++ b/Regression/Checksum/benchmarks_json/test_2d_rigid_injection_btd.json
@@ -1,22 +1,22 @@
 {
+  "lev=0": {
+    "Bx": 3.719030475087696e-05,
+    "By": 0.004843257051761486,
+    "Bz": 5.522765606391185e-06,
+    "Ex": 1461264.5033270014,
+    "Ey": 11205.64142004876,
+    "Ez": 282020.7784731542,
+    "jx": 16437877.898892798,
+    "jy": 2492340.3149980744,
+    "jz": 215102423.57036853,
+    "rho": 0.7246235591902171
+  },
   "beam": {
-    "particle_momentum_x": 2.2080215038948936e-16,
+    "particle_momentum_x": 2.2080215038948934e-16,
     "particle_momentum_y": 2.18711072170811e-16,
-    "particle_momentum_z": 2.730924530737497e-15,
-    "particle_position_x": 0.0260823588888081,
+    "particle_momentum_z": 2.730924530737456e-15,
+    "particle_position_x": 0.026082358888808558,
     "particle_position_y": 0.5049438607316916,
     "particle_weight": 62415.090744607645
-  },
-  "lev=0": {
-    "Bx": 3.721807007218884e-05,
-    "By": 0.004860056238272468,
-    "Bz": 5.5335765596325185e-06,
-    "Ex": 1466447.517373168,
-    "Ey": 11214.10223280318,
-    "Ez": 283216.0961218869,
-    "jx": 16437877.898892513,
-    "jy": 2492340.3149980404,
-    "jz": 215102423.57036877,
-    "rho": 0.7246235591902177
   }
 }
\ No newline at end of file
diff --git a/Source/Diagnostics/BTDiagnostics.cpp b/Source/Diagnostics/BTDiagnostics.cpp
index 631de298861..f10f337a1f1 100644
--- a/Source/Diagnostics/BTDiagnostics.cpp
+++ b/Source/Diagnostics/BTDiagnostics.cpp
@@ -999,12 +999,15 @@ BTDiagnostics::GetZSliceInDomainFlag (const int i_buffer, const int lev)
 {
     auto & warpx = WarpX::GetInstance();
     const amrex::RealBox& boost_domain = warpx.Geom(lev).ProbDomain();
+    const amrex::Real boost_cellsize = warpx.Geom(lev).CellSize(m_moving_window_dir);
     const amrex::Real buffer_zmin_lab = m_snapshot_domain_lab[i_buffer].lo( m_moving_window_dir );
     const amrex::Real buffer_zmax_lab = m_snapshot_domain_lab[i_buffer].hi( m_moving_window_dir );
 
+    // Exclude 0.5*boost_cellsize from the edge, to avoid that the interpolation to
+    // cell centers uses data from the guard cells.
     const bool slice_not_in_domain =
-        ( m_current_z_boost[i_buffer] <= boost_domain.lo(m_moving_window_dir) ) ||
-        ( m_current_z_boost[i_buffer] >= boost_domain.hi(m_moving_window_dir) ) ||
+        ( m_current_z_boost[i_buffer] <= boost_domain.lo(m_moving_window_dir) + 0.5_rt*boost_cellsize) ||
+        ( m_current_z_boost[i_buffer] >= boost_domain.hi(m_moving_window_dir) - 0.5_rt*boost_cellsize) ||
         ( m_current_z_lab[i_buffer] <= buffer_zmin_lab ) ||
         ( m_current_z_lab[i_buffer] >= buffer_zmax_lab );