diff --git a/src/makeint.h b/src/makeint.h
index b8dbc1ff..00dded16 100644
--- a/src/makeint.h
+++ b/src/makeint.h
@@ -537,6 +537,8 @@ void perror_with_name (const char *, const char *);
 unsigned int make_toui (const char*, const char**);
 char *make_lltoa (long long, char *);
 char *make_ulltoa (unsigned long long, char *);
+void make_seed (unsigned int);
+unsigned int make_rand ();
 pid_t make_pid ();
 void *xmalloc (size_t);
 void *xcalloc (size_t);
diff --git a/src/misc.c b/src/misc.c
index 8f9be328..48e4cb5e 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -78,6 +78,35 @@ make_ulltoa (unsigned long long val, char *buf)
   return buf;
 }
 
+/* Simple random number generator, for use with shuffle.
+   This doesn't need to be truly random, just pretty random.  Use our own
+   implementation rather than relying on the C runtime's rand() so we always
+   get the same results for a given seed, regardless of OS.  */
+
+static unsigned int mk_state = 0;
+
+void
+make_seed(unsigned int seed)
+{
+  mk_state = seed;
+}
+
+unsigned int
+make_rand()
+{
+  /* mk_state must never be 0.  */
+  if (mk_state == 0) {
+    mk_state = (unsigned int)(time (NULL) ^ make_pid ()) + 1;
+  }
+
+  /* A simple xorshift RNG.  */
+  mk_state ^= mk_state << 13;
+  mk_state ^= mk_state >> 17;
+  mk_state ^= mk_state << 5;
+
+  return mk_state;
+}
+
 /* Compare strings *S1 and *S2.
    Return negative if the first is less, positive if it is greater,
    zero if they are equal.  */
diff --git a/src/shuffle.c b/src/shuffle.c
index 95f60bea..5f68caf6 100644
--- a/src/shuffle.c
+++ b/src/shuffle.c
@@ -82,9 +82,7 @@ shuffle_set_mode (const char *cmdarg)
     }
   else
     {
-      if (strcasecmp (cmdarg, "random") == 0)
-        config.seed = (unsigned int) (time (NULL) ^ make_pid ());
-      else
+      if (strcasecmp (cmdarg, "random") != 0)
         {
           /* Assume explicit seed.  */
           const char *err;
@@ -109,7 +107,7 @@ random_shuffle_array (void **a, size_t len)
       void *t;
 
       /* Pick random element and swap. */
-      unsigned int j = rand () % len;
+      unsigned int j = make_rand () % len;
       if (i == j)
         continue;
 
@@ -227,7 +225,7 @@ shuffle_deps_recursive (struct dep *deps)
 
   /* Set specific seed at the top level of recursion.  */
   if (config.mode == sm_random)
-    srand (config.seed);
+    make_seed (config.seed);
 
   shuffle_deps (deps);