diff --git a/Source/Initialization/WarpXInitData.cpp b/Source/Initialization/WarpXInitData.cpp
index eea5f088dc1..0e63dd81238 100644
--- a/Source/Initialization/WarpXInitData.cpp
+++ b/Source/Initialization/WarpXInitData.cpp
@@ -785,7 +785,7 @@ WarpX::InitLevelData (int lev, Real /*time*/)
 
         // Externally imposed fields are only initialized until the user-defined maxlevel_extEMfield_init.
         // The default maxlevel_extEMfield_init value is the total number of levels in the simulation
-        if ( ( B_ext_grid_s == "constant" && (lev > maxlevel_extEMfield_init) )
+        if ( ( B_ext_grid_s == "constant" && (lev <= maxlevel_extEMfield_init) )
             || B_ext_grid_s == "default")
         {
            Bfield_fp[lev][i]->setVal(B_external_grid[i]);
@@ -803,7 +803,7 @@ WarpX::InitLevelData (int lev, Real /*time*/)
         }
         // Externally imposed fields are only initialized until the user-defined maxlevel_extEMfield_init.
         // The default maxlevel_extEMfield_init value is the total number of levels in the simulation
-        if ( ( E_ext_grid_s == "constant" && (lev > maxlevel_extEMfield_init) )
+        if ( ( E_ext_grid_s == "constant" && (lev <= maxlevel_extEMfield_init) )
             || E_ext_grid_s == "default")
         {
            Efield_fp[lev][i]->setVal(E_external_grid[i]);
@@ -830,7 +830,7 @@ WarpX::InitLevelData (int lev, Real /*time*/)
     // provided in the input file.
     // Externally imposed fields are only initialized until the user-defined maxlevel_extEMfield_init.
     // The default maxlevel_extEMfield_init value is the total number of levels in the simulation
-    if (B_ext_grid_s == "parse_b_ext_grid_function" && (lev > maxlevel_extEMfield_init)) {
+    if (B_ext_grid_s == "parse_b_ext_grid_function" && (lev <= maxlevel_extEMfield_init)) {
 
 #ifdef WARPX_DIM_RZ
        WARPX_ABORT_WITH_MESSAGE(
@@ -896,7 +896,7 @@ WarpX::InitLevelData (int lev, Real /*time*/)
     // provided in the input file.
     // Externally imposed fields are only initialized until the user-defined maxlevel_extEMfield_init.
     // The default maxlevel_extEMfield_init value is the total number of levels in the simulation
-    if (E_ext_grid_s == "parse_e_ext_grid_function" && (lev > maxlevel_extEMfield_init)) {
+    if (E_ext_grid_s == "parse_e_ext_grid_function" && (lev <= maxlevel_extEMfield_init)) {
 
 #ifdef WARPX_DIM_RZ
        WARPX_ABORT_WITH_MESSAGE(