diff --git a/net/kerberos5/Portfile b/net/kerberos5/Portfile
index 642f6f801bc..4f4d993d38f 100644
--- a/net/kerberos5/Portfile
+++ b/net/kerberos5/Portfile
@@ -44,6 +44,7 @@ worksrcdir                  ${worksrcdir}/src
 patchfiles                  patch-util__verto__Makefile.in-use-nonzero-compat-version.diff \
                             patch-config__shlib.conf-do-not-pass-dylib-file-ldflags.diff \
                             patch-lib_rpc_Makefile.in-explicitly-link-krb5support.diff \
+                            autoconf-2.73.patch \
                             no-Werror.patch \
                             udppktinfo.c.patch
 
diff --git a/net/kerberos5/files/autoconf-2.73.patch b/net/kerberos5/files/autoconf-2.73.patch
new file mode 100644
index 00000000000..ee283ebe8dc
--- /dev/null
+++ b/net/kerberos5/files/autoconf-2.73.patch
@@ -0,0 +1,74 @@
+Make configure.ac work with autoconf 2.73
+
+autoreconf requires "AC_INIT" to appear in configure.ac. Prior to autoconf 2.73,
+our indirect invocation via K5_AC_INIT() was sufficient, but now the regular
+expression match checks for word boundaries. Get rid of K5_AC_INIT(), moving the
+version extraction code from aclocal.m4 to a new file version.m4. In the moved
+versioning code, use m4_fatal() to simplify error handling.
+
+Fixes:
+
+autoreconf: error: configure.ac: AC_INIT not found; not an autoconf script?
+
+https://krbdev.mit.edu/rt/Ticket/Display.html?id=9202
+https://github.com/krb5/krb5/commit/b7290e0cab5b7e39cd4aa7c098beb18a886d4a1d
+--- aclocal.m4
++++ aclocal.m4
+@@ -16,30 +16,6 @@ ac_config_fragdir=$ac_reltopdir/config
+ AC_CONFIG_AUX_DIR(K5_TOPDIR/config)
+ ])dnl
+ dnl
+-dnl Version info.
+-dnl
+-pushdef([x],esyscmd([sed -n 's/#define \([A-Z0-9_]*\)[ \t]*\(.*\)/\1=\2/p' < ]K5_TOPDIR/patchlevel.h))
+-define([PL_KRB5_MAJOR_RELEASE],regexp(x,[KRB5_MAJOR_RELEASE=\(.*\)],[\1]))
+-ifelse(PL_KRB5_MAJOR_RELEASE,,[errprint([Can't determine KRB5_MAJOR_RELEASE value from patchlevel.h.
+-]) m4exit(1) dnl sometimes that does not work?
+-builtin(m4exit,1)])
+-define([PL_KRB5_MINOR_RELEASE],regexp(x,[KRB5_MINOR_RELEASE=\(.*\)],[\1]))
+-ifelse(PL_KRB5_MINOR_RELEASE,,[errprint([Can't determine KRB5_MINOR_RELEASE value from patchlevel.h.
+-]) m4exit(1) dnl sometimes that does not work?
+-builtin(m4exit,1)])
+-define([PL_KRB5_PATCHLEVEL],regexp(x,[KRB5_PATCHLEVEL=\(.*\)],[\1]))
+-ifelse(PL_KRB5_PATCHLEVEL,,[errprint([Can't determine KRB5_PATCHLEVEL value from patchlevel.h.
+-]) m4exit(1) dnl sometimes that does not work?
+-builtin(m4exit,1)])
+-define([PL_KRB5_RELTAIL],regexp(x,[KRB5_RELTAIL="\(.*\)"],[\1]))
+-dnl RELTAIL is allowed to not be defined.
+-popdef([x])
+-define([K5_VERSION],PL_KRB5_MAJOR_RELEASE.PL_KRB5_MINOR_RELEASE[]ifelse(PL_KRB5_PATCHLEVEL,0,,.PL_KRB5_PATCHLEVEL)ifelse(PL_KRB5_RELTAIL,,,-PL_KRB5_RELTAIL))
+-define([K5_BUGADDR],krb5-bugs@mit.edu)
+-define([K5_AC_INIT],[AC_INIT(Kerberos 5, K5_VERSION, K5_BUGADDR, krb5)
+-AC_CONFIG_SRCDIR($1)
+-build_dynobj=no])
+-dnl
+ dnl drop in standard rules for all configure files -- CONFIG_RULES
+ dnl
+ AC_DEFUN(CONFIG_RULES,[dnl
+--- configure.ac
++++ configure.ac
+@@ -1,4 +1,6 @@
+-K5_AC_INIT([aclocal.m4])
++m4_include([version.m4])
++AC_INIT(Kerberos 5, K5_VERSION, K5_BUGADDR, krb5)
++AC_CONFIG_SRCDIR([aclocal.m4])
+ 
+ # If $runstatedir isn't set by autoconf (<2.70), set it manually.
+ if test x"$runstatedir" = x; then
+--- /dev/null
++++ version.m4
+@@ -0,0 +1,14 @@
++define([K5_TOPDIR],[.])dnl
++dnl
++pushdef([x],esyscmd([sed -n 's/#define \([A-Z0-9_]*\)[ \t]*\(.*\)/\1=\2/p' < ]K5_TOPDIR/patchlevel.h))
++define([PL_KRB5_MAJOR_RELEASE],regexp(x,[KRB5_MAJOR_RELEASE=\(.*\)],[\1]))
++ifelse(PL_KRB5_MAJOR_RELEASE,,[m4_fatal([Can't determine KRB5_MAJOR_RELEASE value from patchlevel.h.])])
++define([PL_KRB5_MINOR_RELEASE],regexp(x,[KRB5_MINOR_RELEASE=\(.*\)],[\1]))
++ifelse(PL_KRB5_MINOR_RELEASE,,[m4_fatal([Can't determine KRB5_MINOR_RELEASE value from patchlevel.h.])])
++define([PL_KRB5_PATCHLEVEL],regexp(x,[KRB5_PATCHLEVEL=\(.*\)],[\1]))
++ifelse(PL_KRB5_PATCHLEVEL,,[m4_fatal([Can't determine KRB5_PATCHLEVEL value from patchlevel.h.])])
++define([PL_KRB5_RELTAIL],regexp(x,[KRB5_RELTAIL="\(.*\)"],[\1]))
++dnl RELTAIL is allowed to not be defined.
++popdef([x])
++m4_define([K5_VERSION],PL_KRB5_MAJOR_RELEASE.PL_KRB5_MINOR_RELEASE[]ifelse(PL_KRB5_PATCHLEVEL,0,,.PL_KRB5_PATCHLEVEL)ifelse(PL_KRB5_RELTAIL,,,-PL_KRB5_RELTAIL))
++m4_define([K5_BUGADDR],krb5-bugs@mit.edu)
diff --git a/net/kerberos5/files/no-Werror.patch b/net/kerberos5/files/no-Werror.patch
index 2ef5d110295..8742bb412e1 100644
--- a/net/kerberos5/files/no-Werror.patch
+++ b/net/kerberos5/files/no-Werror.patch
@@ -1,6 +1,6 @@
---- aclocal.m4.orig	2026-01-30 10:18:10
-+++ aclocal.m4	2026-03-15 02:31:20
-@@ -475,10 +475,6 @@
+--- aclocal.m4
++++ aclocal.m4
+@@ -451,10 +451,6 @@
  dnl get reported as errors?
  AC_DEFUN(CHECK_CC_WARNING_TEST_FLAGS,[dnl
    cflags_warning_test_flags=
@@ -11,7 +11,7 @@
  ])dnl
  dnl
  AC_DEFUN(TRY_WARN_CC_FLAG,[dnl
-@@ -548,7 +544,7 @@
+@@ -524,7 +520,7 @@
      TRY_WARN_CC_FLAG(-Wno-format-zero-length)
      # Other flags here may not be supported on some versions of
      # gcc that people want to use.
@@ -20,7 +20,7 @@
        TRY_WARN_CC_FLAG(-W$flag)
      done
      #  old-style-definition? generates many, many warnings
-@@ -565,10 +561,7 @@
+@@ -541,10 +537,7 @@
      # We're currently targeting C89+, not C99, so disallow some
      # constructs.
      for flag in declaration-after-statement ; do
@@ -31,7 +31,7 @@
      done
      # We require function declarations now.
      #
-@@ -577,10 +570,6 @@
+@@ -553,10 +546,6 @@
      # version doesn't cause implicitly declared functions to be
      # flagged as errors.  If neither works, -Wall implies
      # -Wimplicit-function-declaration so don't bother.