Index: crypt.setup
===================================================================
--- crypt.setup (revision 26456)
+++ crypt.setup (working copy)
@@ -40,8 +40,8 @@
    (pp known-hash-types)
    (print "================================================================\n"))
  
- ((try-compile libcrypt-presence-checker ldflags: "-lcrypt")
-  (compile -L -lcrypt detect-native-crypt-features.scm)
+ ((try-compile libcrypt-presence-checker cflags: "-D_XOPEN_SOURCE" ldflags: "-lcrypt")
+  (compile -C -D_XOPEN_SOURCE -L -lcrypt detect-native-crypt-features.scm)
   (run (./detect-native-crypt-features))
   (let ((features (with-input-from-file "crypt-features" read)))
     ;; Useful for debugging
@@ -60,7 +60,7 @@
 (let* ((feature-flags (intersperse *compile-features* '-feature))
        (flags (if (null? feature-flags) '() `(-feature has-native-crypt
                                                        -feature ,@feature-flags))))
-  (compile -s -O2 crypt.scm -L -lcrypt ,@flags -j crypt))
+  (compile -s -O2 crypt.scm -L -lcrypt -C -D_XOPEN_SOURCE ,@flags -j crypt))
 
 (compile -s -O2 crypt.import.scm)