diff --git a/src/Rules.LXgfortran.mk b/src/Rules.LXgfortran.mk
index 708d9ba2f1a8dc488398ea06b0af5a61c790018d..84931b74e9edbbdb701b7235f00e161307ec3736 100644
--- a/src/Rules.LXgfortran.mk
+++ b/src/Rules.LXgfortran.mk
@@ -22,6 +22,11 @@ OPT_I8    = -fdefault-integer-8
 OPT_R8    = -fdefault-real-8 -fdefault-double-8
 OPT_OPENACC = -fopenacc
 #
+ifeq "$(VER_USER)" "ZSOLVER"
+CPPFLAGS  += -DCARTESIANGEOMETRY -DPIECEWISELINEAR
+#  -DOVERLAPCOMMS
+PROG_LIST += MG_MAIN MG_MAIN_MNH_ALL
+endif
 #
 # Real/Integer 4/8 option
 #
@@ -115,6 +120,11 @@ CNAME_GRIBEX=_gfortran
 HDF_CONF= CFLAGS=-std=c99
 HDF_OPT ?= -fPIC
 NETCDF_OPT ?= -fPIC
+#if MNH_BITREP exists => compile with the BITREP library
+ifeq "$(MNH_BITREP)" "YES"
+CPPFLAGS_MNH += -DMNH_BITREP
+endif
+
 #
 ## LIBTOOLS flags
 #