diff --git a/Build.sh b/Build.sh
index 035bef1..35dc807 100644
--- a/Build.sh
+++ b/Build.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-srcversion='$MirOS: src/bin/mksh/Build.sh,v 1.454 2010/07/04 17:45:10 tg Exp $'
+srcversion='$MirOS: src/bin/mksh/Build.sh,v 1.455 2010/07/18 17:29:49 tg Exp $'
 #-
 # Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
 #	Thorsten Glaser <tg@mirbsd.org>
@@ -29,7 +29,7 @@ srcversion='$MirOS: src/bin/mksh/Build.sh,v 1.454 2010/07/04 17:45:10 tg Exp $'
 #			MKSH_CONSERVATIVE_FDS MKSH_MIDNIGHTBSD01ASH_COMPAT
 #			MKSH_NOPWNAM MKSH_NO_LIMITS MKSH_SMALL MKSH_S_NOVI
 #			MKSH_UNEMPLOYED MKSH_DEFAULT_EXECSHELL MKSHRC_PATH
-#			MKSH_DEFAULT_TMPDIR MKSH_CLRTOEOL_STRING
+#			MKSH_DEFAULT_TMPDIR MKSH_CLRTOEOL_STRING MKSH_A4PB
 
 LC_ALL=C
 export LC_ALL
diff --git a/var.c b/var.c
index 16e94b8..1cab68d 100644
--- a/var.c
+++ b/var.c
@@ -26,7 +26,7 @@
 #include <sys/sysctl.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/var.c,v 1.108 2010/07/17 22:09:40 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/var.c,v 1.109 2010/07/18 17:29:50 tg Exp $");
 
 /*
  * Variables
@@ -1050,6 +1050,16 @@ change_random(const void *vp, size_t n)
 	/* we ignore failures and take in k anyway */
 	h = oaathash_update(h, k, sizeof(k));
 	kshstate_v.lcg_state_ = oaathash_finalise(h);
+#elif defined(MKSH_A4PB)
+	/* forced by the user to use arc4random_pushb(3) • Cygwin? */
+	{
+		uint32_t prv;
+
+		prv = arc4random_pushb(&kshstate_v.lcg_state_,
+		    sizeof(kshstate_v.lcg_state_));
+		h = oaathash_update(h, &prv, sizeof(prv));
+	}
+	kshstate_v.lcg_state_ = oaathash_finalise(h);
 #endif
 }