diff --git a/packages/sda/package.py b/packages/sda/package.py
index b9c9a1981f7b94267158c85732fc23e8f72f2eb8..95c3b73430271c13974b871521b48298637dbfec 100644
--- a/packages/sda/package.py
+++ b/packages/sda/package.py
@@ -39,6 +39,7 @@ class Sda(MakefilePackage):
         makefile = FileFilter('src/Makefile')
         makefile.filter(r'gfortran', spack_fc)
         makefile.filter(r'^\s*FC\s*=.*',  'FC = '  + spack_fc)
+        makefile.filter(r'^CFLAG += -O3', 'CFLAG += -std=gnu++14 -O3')
         makefile.filter(r'^\s*CC_plus\s*=.*', 'CXX = ' + spack_cxx)
         makefile.filter(r'\${CC_plus}', '${CXX}')
         makefile.filter(r'^\s*CC_moins\s*=.*', 'CC = ' + spack_cc)