diff --git a/lib-src/test-distrib.c b/lib-src/test-distrib.c
index 33dc0a46ab4..dc5adb5789c 100644
--- a/lib-src/test-distrib.c
+++ b/lib-src/test-distrib.c
@@ -1,5 +1,14 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <stdio.h>
 
+#ifndef O_RDONLY
+#define O_RDONLY 0
+#endif
+
+
 /* Break string in two parts to avoid buggy C compilers that ignore characters
    after nulls in strings.  */
 
@@ -44,7 +53,7 @@ main (argc, argv)
       fprintf (stderr, "Usage: %s testfile\n", argv[0]);
       exit (2);
     }
-  fd = open (argv[1], 0);
+  fd = open (argv[1], O_RDONLY);
   if (fd < 0)
     {
       perror (argv[1]);