diff --git a/opendbx.spec b/opendbx.spec
index 4460de9..c55e6df 100644
--- a/opendbx.spec
+++ b/opendbx.spec
@@ -231,7 +231,7 @@ export CFLAGS="%{optflags} \
   $(%{_bindir}/mysql_config --include) \
 %endif
   -I$(/usr/bin/pg_config --includedir) -fno-strict-aliasing"
-export CPPFLAGS="$CFLAGS"
+export CPPFLAGS="$CFLAGS --std=c++14"
 %configure \
   --with-pic \
   --disable-static \