diff -up src/sage/libs/lcalc/lcalc_Lfunction.pxd.orig src/sage/libs/lcalc/lcalc_Lfunction.pxd

--- src/sage/libs/lcalc/lcalc_Lfunction.pxd.orig	2018-05-05 16:21:24.000000000 -0600

+++ src/sage/libs/lcalc/lcalc_Lfunction.pxd	2018-05-22 13:31:10.717337490 -0600

@@ -1,6 +1,6 @@

 # Lcalc requires GNU extensions, it does not strictly conform to any

 # C++ standard: https://trac.sagemath.org/ticket/23341

-# distutils: extra_compile_args = -std=gnu++98

+# distutils: extra_compile_args = -std=gnu++11

 cdef extern from "lcalc_sage.h":

     ctypedef struct doublevec "std::vector<double>":

diff -up src/sage/libs/lcalc/lcalc_sage.h.orig src/sage/libs/lcalc/lcalc_sage.h

--- src/sage/libs/lcalc/lcalc_sage.h.orig	2018-05-05 16:21:24.000000000 -0600

+++ src/sage/libs/lcalc/lcalc_sage.h	2018-05-22 13:30:32.012839737 -0600

@@ -1,4 +1,4 @@

-#include "libLfunction/L.h"

+#include "Lfunction/L.h"

 int *new_ints(int l)

 {