diff --git a/util/makedefs.c b/util/makedefs.c
index 44a04a4ff..daaecd61d 100644
--- a/util/makedefs.c
+++ b/util/makedefs.c
@@ -1628,6 +1628,27 @@ static const char *build_opts[] = {
 #endif
     /* pattern matching method will be substituted by nethack at run time */
     "pattern matching via :PATMATCH:",
+#ifdef USE_ISAAC64
+    "pseudo random numbers generated by ISAAC64",
+#ifdef DEV_RANDOM
+#ifdef __STDC__
+    /* include which specific one */
+    "strong PRNG seed available from " DEV_RANDOM,
+#else
+    "strong PRNG seed available from DEV_RANDOM",
+#endif
+#else
+#ifdef WIN32
+    "strong PRNG seed available from CNG BCryptGenRandom()",
+#endif
+#endif  /* DEV_RANDOM */    
+#else   /* ISAAC64 */
+#ifdef RANDOM
+    "pseudo random numbers generated by random()",
+#else
+    "pseudo random numbers generated by C rand()",
+#endif
+#endif
 #ifdef SELECTSAVED
     "restore saved games via menu",
 #endif