diff --git a/src/mesonh/ext/ground_paramn.f90 b/src/mesonh/ext/ground_paramn.f90
index 84022d5892178c5d76356352791891d576d3ce53..5d872413b3361b500da93f8a7671510c51adfdac 100644
--- a/src/mesonh/ext/ground_paramn.f90
+++ b/src/mesonh/ext/ground_paramn.f90
@@ -150,7 +150,7 @@ USE MODD_METRICS_n,  ONLY : XDXX, XDYY, XDZZ
 USE MODD_DIM_n,      ONLY : NKMAX
 USE MODD_GRID_n,     ONLY : XLON, XZZ, XDIRCOSXW, XDIRCOSYW, XDIRCOSZW, &
                             XCOSSLOPE, XSINSLOPE, XZS
-USE MODD_REF_n,      ONLY : XRHODREF,XRHODJ
+USE MODD_REF_n,      ONLY : XRHODREF,XRHODJ,XEXNREF
 USE MODD_CONF_n,     ONLY : NRR
 USE MODD_PARAM_n,    ONLY : CDCONV,CCLOUD, CRAD
 USE MODD_PRECIP_n,   ONLY : XINPRC, XINPRR, XINPRS, XINPRG, XINPRH