diff --git a/lib/isc/random.c b/lib/isc/random.c
index 70d65f05a3..826e50d6dc 100644
--- a/lib/isc/random.c
+++ b/lib/isc/random.c
@@ -107,6 +107,15 @@ isc_random_seed(isc_uint32_t seed) {
 	arc4random_stir();
 #elif defined(HAVE_ARC4RANDOM_ADDRANDOM)
 	arc4random_addrandom((u_char *) &seed, sizeof(isc_uint32_t));
+#else
+       /*
+        * If arcrandom() is available and no corresponding seeding
+        * function arc4random_addrandom() is available, no seeding is
+        * done on such platforms (e.g., OpenBSD 5.5).  This is because
+        * the OS itself is supposed to seed the RNG and it is assumed
+        * that no explicit seeding is required.
+        */
+       UNUSED(seed);
 #endif
 }