--- src/Makevars	2023-12-11 23:53:04.000000000 +0800
+++ src/Makevars	2024-06-01 22:51:53.000000000 +0800
@@ -1,6 +1,6 @@
 # copied from sources of R package gsl
-GSL_CFLAGS = -I/usr/local/include
-GSL_LIBS   = -L/usr/local/lib -lgsl -lgslcblas
+GSL_CFLAGS = -I@PREFIX@/include
+GSL_LIBS   = -L@PREFIX@/lib -lgsl -lgslcblas
 
 # combine to standard arguments for R
 PKG_CFLAGS =  $(GSL_CFLAGS)