diff --git a/src/geometry_mod.F90 b/src/geometry_mod.F90
index 0acf2700980f902412dbd5ffbff136d1b1aa60ee..84bac73585763b75c7b02324628a4cfdeb771488 100644
--- a/src/geometry_mod.F90
+++ b/src/geometry_mod.F90
@@ -326,13 +326,10 @@ CONTAINS
  IMPLICIT NONE
  REAL :: shift, kx_shift
  ! For periodic CHI BC or 0 dirichlet
- LOGICAL :: PERIODIC_CHI_BC = .TRUE.
+ LOGICAL :: PERIODIC_CHI_BC = .FALSE.
  ALLOCATE(ikx_zBC_R(ikys:ikye,ikxs:ikxe))
  ALLOCATE(ikx_zBC_L(ikys:ikye,ikxs:ikxe))
 
- ! No periodic connection for extension of the domain
- IF(Nexc .GT. 1) PERIODIC_CHI_BC = .TRUE.
-
  !! No shear case (simple id mapping)
  !3            | 1    2    3    4    5    6 |  ky = 3 dky
  !2   ky       | 1    2    3    4    5    6 |  ky = 2 dky
diff --git a/src/stepon.F90 b/src/stepon.F90
index 1771985ee4be7ff11d15e3c0a518aff934f41912..529a69c931c5f6069bbd4164fdc7e0fc86e66471 100644
--- a/src/stepon.F90
+++ b/src/stepon.F90
@@ -8,7 +8,6 @@ SUBROUTINE stepon
   USE model, ONLY : LINEARITY, KIN_E
   use prec_const
   USE time_integration
-  USE numerics, ONLY: play_with_modes
   USE utility, ONLY: checkfield
   IMPLICIT NONE
 
@@ -38,10 +37,6 @@ SUBROUTINE stepon
       CALL solve_EM_fields
       CALL update_ghosts_EM
 
-      ! Numerical experiments
-      ! Store or cancel/maintain zonal modes artificially
-      ! CALL play_with_modes
-
       !-  Check before next step
       CALL checkfield_all()
       IF( nlend ) EXIT ! exit do loop