diff --git a/devel/valgrind/files/patch-configure.ac b/devel/valgrind/files/patch-configure.ac
new file mode 100644
--- /dev/null
+++ b/devel/valgrind/files/patch-configure.ac
@@ -0,0 +1,27 @@
+--- configure.ac.orig	2023-04-28 15:28:21 UTC
++++ configure.ac
+@@ -398,6 +398,8 @@ case "${host_os}" in
+         freebsd_13_2=1320
+         AC_DEFINE([FREEBSD_14], 1400, [FREEBSD_VERS value for FreeBSD 14.x])
+         freebsd_14=1400
++        AC_DEFINE([FREEBSD_15], 1500, [FREEBSD_VERS value for FreeBSD 15.x])
++        freebsd_15=1500
+ 
+         AC_MSG_CHECKING([for the kernel version])
+         kernel=`uname -r`
+@@ -451,9 +453,14 @@ case "${host_os}" in
+            AC_DEFINE([FREEBSD_VERS], FREEBSD_14, [FreeBSD version])
+            freebsd_vers=$freebsd_14
+            ;;
++        15.*)
++           AC_MSG_RESULT([FreeBSD 15.x (${kernel})])
++           AC_DEFINE([FREEBSD_VERS], FREEBSD_15, [FreeBSD version])
++           freebsd_vers=$freebsd_15
++           ;;
+         *)
+            AC_MSG_RESULT([unsupported (${kernel})])
+-           AC_MSG_ERROR([Valgrind works on FreeBSD 10.x to 14.x])
++           AC_MSG_ERROR([Valgrind works on FreeBSD 10.x to 15.x])
+            ;;
+         esac
+