diff --git a/sysdep/unix/Doc b/sysdep/unix/Doc
index d4dab05f..5ab11b4c 100644
--- a/sysdep/unix/Doc
+++ b/sysdep/unix/Doc
@@ -1,4 +1,4 @@
 H UNIX system dependent parts
-S io.c
 S log.c
 S krt.c
+# io.c is documented under Resources
diff --git a/sysdep/unix/Modules b/sysdep/unix/Modules
index 017623e7..2666f9d6 100644
--- a/sysdep/unix/Modules
+++ b/sysdep/unix/Modules
@@ -5,6 +5,7 @@ io.c
 unix.h
 endian.h
 config.Y
+random.c
 
 krt.c
 krt.h
diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 9d80b7dd..ca233113 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -28,20 +28,6 @@
 #include "lib/unix.h"
 #include "lib/sysio.h"
 
-/*
- *	Random Numbers
- */
-
-u32
-random_u32(void)
-{
-  long int rand_low, rand_high;
-
-  rand_low = random();
-  rand_high = random();
-  return (rand_low & 0xffff) | ((rand_high & 0xffff) << 16);
-}
-
 /*
  *	Tracked Files
  */
diff --git a/sysdep/unix/random.c b/sysdep/unix/random.c
new file mode 100644
index 00000000..b1f5086f
--- /dev/null
+++ b/sysdep/unix/random.c
@@ -0,0 +1,21 @@
+/*
+ *	BIRD Internet Routing Daemon -- Random Numbers
+ *
+ *	(c) 2000 Martin Mares <mj@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include <stdlib.h>
+
+#include "nest/bird.h"
+
+u32
+random_u32(void)
+{
+  long int rand_low, rand_high;
+
+  rand_low = random();
+  rand_high = random();
+  return (rand_low & 0xffff) | ((rand_high & 0xffff) << 16);
+}