diff --git a/src/Rules.LXgfortran.mk b/src/Rules.LXgfortran.mk
index 73839121f600b5bf5ff025c40f66e2e3789a9dc6..e9cbd402ee9addfc59c1d57e03769cd046b81135 100644
--- a/src/Rules.LXgfortran.mk
+++ b/src/Rules.LXgfortran.mk
@@ -75,6 +75,7 @@ FX90FLAGS     =  $(OPT)
 #
 CPP = cpp -P -traditional -Wcomment
 #
+CPPFLAGS_C         = -DLITTLE_endian
 CPPFLAGS_SURFEX    =
 CPPFLAGS_SURCOUCHE += -DDEV_NULL
 CPPFLAGS_RAD       =
diff --git a/src/Rules.LXifort.mk b/src/Rules.LXifort.mk
index b7f8e24bdb1236b64d9c9ed0346b2a463f8066b9..902023b0d45ee93f992e9cf2e7b403640a6cce1e 100644
--- a/src/Rules.LXifort.mk
+++ b/src/Rules.LXifort.mk
@@ -172,6 +172,7 @@ LDFLAGS    =   -Wl,--allow-multiple-definition -Wl,-warn-once $(PAR) -Wl,-rpath=
 #
 CPP = cpp -P -traditional -Wcomment
 #
+CPPFLAGS_C         = -DLITTLE_endian
 CPPFLAGS_SURFEX    =
 CPPFLAGS_SURCOUCHE += -DDEV_NULL
 CPPFLAGS_RAD       =