diff --git a/configure.ac b/configure.ac
index 031be4a..2831e59 100644
--- a/configure.ac
+++ b/configure.ac
@@ -79,7 +79,7 @@
 
 # Functions, and headers
 
-AC_CHECK_FUNCS(atexit mprotect sysconf getpagesize mmap isatty newlocale strtod_l setlinebuf)
+AC_CHECK_FUNCS(atexit mprotect sysconf getpagesize mmap isatty newlocale strtod_l)
 
 save_libs="$LIBS"
 LIBS="$LIBS -lm"
diff --git a/util/options.cc b/util/options.cc
index db7115c..027d0b3 100644
--- a/util/options.cc
+++ b/util/options.cc
@@ -803,12 +803,6 @@
     gs = g_string_new (nullptr);
   }
 
-#ifdef HAVE_SETLINEBUF
-  setlinebuf (fp);
-#else
-  setvbuf(fp, NULL, _IOLBF, BUFSIZ);
-#endif
-
   g_string_set_size (gs, 0);
   char buf[BUFSIZ];
   while (fgets (buf, sizeof (buf), fp)) {
@@ -846,12 +840,6 @@
     fail (false, "Cannot open output file `%s': %s",
 	  g_filename_display_name (output_file), strerror (errno));
 
-#ifdef HAVE_SETLINEBUF
-  setlinebuf (fp);
-#else
-  setvbuf(fp, NULL, _IOLBF, BUFSIZ);
-#endif
-
   return fp;
 }