diff --git a/Mk/bsd.default-versions.mk b/Mk/bsd.default-versions.mk
index bac02f9ab86a..fcd3db1a94e0 100644
--- a/Mk/bsd.default-versions.mk
+++ b/Mk/bsd.default-versions.mk
@@ -88,7 +88,11 @@ LIBRSVG2_DEFAULT?=	rust
 LIBRSVG2_DEFAULT?=	legacy
 .  endif
 # Possible values: c7 rl9
+.  if ${ARCH:Mi386}
 LINUX_DEFAULT?=		c7
+.  else
+LINUX_DEFAULT?=		rl9
+.  endif
 # Possible values: 11, 12, 13, 14, 15, 16, 17, 18, 19, -devel (to be used when non-base compiler is required)
 LLVM_DEFAULT?=		19
 # Possible values: 5.1, 5.2, 5.3, 5.4
diff --git a/UPDATING b/UPDATING
index 9e398da95db7..d2b724debb7c 100644
--- a/UPDATING
+++ b/UPDATING
@@ -5,6 +5,19 @@ they are unavoidable.
 You should get into the habit of checking this file for changes each time
 you update your ports collection, before attempting any port upgrades.
 
+20250408:
+  AFFECTS: users of linux_base-c7 and any Linux application in Ports
+  AUTHOR: arrowd@FreeBSD.org
+
+  LINUX_DEFAULT was switched to "rl9" which correspons to the Rocky Linux 9 base.
+  All architectures except i386 are affected. To stay on the old base add
+  DEFAULT_VERSIONS=linux=c7 to your /etc/make.conf
+
+  Note that some older amd64 hardware (pre-Nehalem) might not support the
+  instruction set that is targeted by Rocky Linux builders. If you're getting
+  SIGILL crashes when running Linux apps consider switching LINUX_DEFAULT back
+  to "c7".
+
 20250404:
   AFFECTS: users of jetbrains-clion
   AUTHOR: fernape@FreeBSD.org