diff --git a/src/Makefile b/src/Makefile
index a89aa69e85326f4698bcb3382af8df7bc8dfbefc..ae3e72dcfed94b78fc24009f63b197b08ea4b33e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -332,9 +332,9 @@ ifeq "$(VER_CDF)" "CDFAUTO"
 cdf : $(CDF_INC)
 $(CDF_INC) : 
 	cd ${DIR_HDF} && ./configure --disable-shared --prefix=${CDF_PATH} --libdir=${CDF_PATH}/lib64 --with-zlib=no \
-	FC="$(FC)" FCFLAGS="$(OPT_BASE)" CPPFLAGS="-DpgiFortran" && make && make install 
+	FC="$(FC)" FCFLAGS="$(OPT_BASE)" CPPFLAGS="-DpgiFortran" ${HDF_CONF} && make && make install 
 	cd ${DIR_CDF} && ./configure --disable-shared --prefix=${CDF_PATH} --libdir=${CDF_PATH}/lib64 --disable-cxx --disable-f90 --disable-dap \
-	FC="$(FC)" FCFLAGS="$(OPT_BASE)" CPPFLAGS="-DpgiFortran ${INC_NETCDF}" LDFLAGS=" -L${CDF_PATH}/lib64" && make && make install 
+	FC="$(FC)" FCFLAGS="$(OPT_BASE)" CPPFLAGS="-DpgiFortran ${INC_NETCDF}" ${CDF_CONF} LDFLAGS=" -L${CDF_PATH}/lib64" && make && make install 
 
 cleanmaster : cleancdf
 cleancdf :
diff --git a/src/Rules.LXgfortran.mk b/src/Rules.LXgfortran.mk
index 0641238a3e1e057a2811ee9ad4a51930ab601fea..7a01c286bb2a4568f2c73f45b7c029e0026aa3f5 100644
--- a/src/Rules.LXgfortran.mk
+++ b/src/Rules.LXgfortran.mk
@@ -86,6 +86,10 @@ endif
 #
 TARGET_GRIBEX=linux
 CNAME_GRIBEX=_gfortran
+#
+# Netcdf/HDF5 flags
+#
+HDF_CONF= CFLAGS=-std=c99
 ##########################################################
 #                                                        #
 # Source of MESONH PACKAGE  Distribution                 #