diff --git a/Source/WarpX.H b/Source/WarpX.H
index 54e1bf430a1..c092d95589c 100644
--- a/Source/WarpX.H
+++ b/Source/WarpX.H
@@ -159,7 +159,7 @@ public:
     //! User-defined parser to initialize z-component of the electric field on the grid
     std::unique_ptr<amrex::Parser> Ezfield_parser;
 
-    /** Maximum level upto which the externally defined electric and magnetic fields are initialized.
+    /** Maximum level up to which the externally defined electric and magnetic fields are initialized.
      *  The default value is set to the max levels in the simulation.
      *  if lev > maxlevel_extEMfield_init, the fields on those levels will have a default value of 0
      */