diff --git a/doc/Changelog b/doc/Changelog
index 2f77b13..84db052 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -64,6 +64,9 @@ sysvinit (2.89dsf) UNRELEASED; urgency=low
   * Move dovoid() macro from #ifdef__GLIBC__ to #ifdef __linux__,
     to match the condutions of the place where it is used.  Thanks
     to Matias A. Fonzo for noticing.
+  * Define _XOPEN_SOURCE when building to get crypt() from <unistd.h>
+    instead of using <crypt.h> in sulogin.c, to get the source building
+    with the musl C library.
 
  -- Petter Reinholdtsen <pere@hungry.com>  Sun Apr 11 11:28:55 CEST 2010
 
diff --git a/src/Makefile b/src/Makefile
index 9d17feb..2189eeb 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -10,7 +10,7 @@
 
 CPPFLAGS =
 CFLAGS	?= -ansi -O2 -fomit-frame-pointer
-override CFLAGS += -W -Wall -D_GNU_SOURCE
+override CFLAGS += -W -Wall -D_XOPEN_SOURCE -D_GNU_SOURCE
 STATIC	=
 MANDB	:= s@^\('\\\\\"\)[^\*-]*-\*- coding: [^[:blank:]]\+ -\*-@\1@
 
diff --git a/src/sulogin.c b/src/sulogin.c
index 66dfd2c..68c2aa9 100644
--- a/src/sulogin.c
+++ b/src/sulogin.c
@@ -44,9 +44,6 @@
 #include <sys/ttydefaults.h>
 #include <errno.h>
 #include <sys/ioctl.h>
-#if defined(__GLIBC__)
-#  include <crypt.h>
-#endif
 #ifdef __linux__
 #  include <sys/statfs.h>
 #  include <sys/mount.h>