diff --git a/sysutils/cbsd/files/patch-bin_cbsdsh_src_mksignames.c b/sysutils/cbsd/files/patch-bin_cbsdsh_src_mksignames.c
new file mode 100644
index 000000000000..ecdba6e7b236
--- /dev/null
+++ b/sysutils/cbsd/files/patch-bin_cbsdsh_src_mksignames.c
@@ -0,0 +1,13 @@
+--- bin/cbsdsh/src/mksignames.c.orig	2026-09-16 08:21:34 UTC
++++ bin/cbsdsh/src/mksignames.c
+@@ -44,6 +44,10 @@ char *progname;
+    I don't want to allocate so much unused space for the intervening signal
+    numbers, so we just punt if SIGRTMAX is past the bounds of the
+    signal_names array (handled in configure). */
++#if defined (SIGRTMAX) && !defined (UNUSABLE_RT_SIGNALS) && (SIGRTMAX >= 2 * NSIG + 3)
++#  define UNUSABLE_RT_SIGNALS
++#endif
++
+ #if defined (SIGRTMAX) && defined (UNUSABLE_RT_SIGNALS)
+ #  undef SIGRTMAX
+ #  undef SIGRTMIN