diff --git a/src/scandir_posix.c b/src/scandir_posix.c
index af33612e2..ec0c84173 100644
--- a/src/scandir_posix.c
+++ b/src/scandir_posix.c
@@ -33,6 +33,8 @@
  */
 
 #include <config.h>
+#if defined(USE_X11) && !defined(HAVE_SCANDIR)
+
 #ifndef HAVE_PTHREAD
    /* Switch system headers into POSIX.1-1990 mode */
 #  define _POSIX_SOURCE
@@ -201,6 +203,8 @@ fl_scandir(const char *dir, struct dirent ***namelist,
   return result;
 }
 
+#endif // defined(USE_X11) && !defined(HAVE_SCANDIR)
+
 /*
  * End of "$Id$".
  */