diff --git a/UPGRADING.INTERNALS b/UPGRADING.INTERNALS
index 432754528f09..da3b88c10fb4 100644
--- a/UPGRADING.INTERNALS
+++ b/UPGRADING.INTERNALS
@@ -49,12 +49,18 @@ PHP 8.5 INTERNALS UPGRADE NOTES
     without duplicate build rules.  It is up to the SAPI maintainers to ensure
     that appropriate build rules are created.
 
-- Linux build system changes
+- Unix build system changes
   . libdir is properly set when --libdir (ex: /usr/lib64) and --with-libdir (ex lib64)
     configure options are used to ${libdir}/php (ex: /usr/lib64/php)
   . PHP_ODBC_CFLAGS, PHP_ODBC_LFLAGS, PHP_ODBC_LIBS, PHP_ODBC_TYPE preprocessor
     macros defined by ext/odbc are now defined in php_config.h instead of the
     build-defs.h header.
+  . Autoconf macro PHP_AP_EXTRACT_VERSION has been removed.
+  . Autoconf macro PHP_BUILD_THREAD_SAFE has been removed (set enable_zts
+    manually).
+  . Autoconf macro PHP_DEF_HAVE has been removed (use AC_DEFINE).
+  . Autoconf macro PHP_OUTPUT has been removed (use AC_CONFIG_FILES).
+  . Autoconf macro PHP_TEST_BUILD has been removed (use AC_* macros).
 
 ========================
 3. Module changes
diff --git a/build/php.m4 b/build/php.m4
index aa49766fedd7..8cdf318083fb 100644
--- a/build/php.m4
+++ b/build/php.m4
@@ -26,15 +26,6 @@ dnl ----------------------------------------------------------------------------
 dnl Build system helper macros.
 dnl ----------------------------------------------------------------------------
 
-dnl
-dnl PHP_DEF_HAVE(what)
-dnl
-dnl Generates 'AC_DEFINE(HAVE_WHAT, 1, [ ])'.
-dnl
-AC_DEFUN([PHP_DEF_HAVE], [m4_warn([obsolete],
-  [The macro 'PHP_DEF_HAVE' is obsolete. Use AC_DEFINE.])
-AC_DEFINE([HAVE_]translit($1,a-z_.-,A-Z___), 1, [ ])])
-
 dnl
 dnl PHP_RUN_ONCE(namespace, variable, code)
 dnl
@@ -89,17 +80,6 @@ AC_DEFUN([PHP_SUBST_OLD],[
   PHP_SUBST([$1])
 ])
 
-dnl
-dnl PHP_OUTPUT(file)
-dnl
-dnl Adds "file" to the list of files generated by AC_OUTPUT. This macro can be
-dnl used several times. This macro is obsolete as of PHP 8.4 in favor of the
-dnl default AC_CONFIG_FILES.
-dnl
-AC_DEFUN([PHP_OUTPUT],
-[m4_warn([obsolete], [The macro 'PHP_OUTPUT' is obsolete. Use AC_CONFIG_FILES.])
-AC_CONFIG_FILES([$1])])
-
 dnl ----------------------------------------------------------------------------
 dnl Build system base macros.
 dnl ----------------------------------------------------------------------------
@@ -743,13 +723,6 @@ dnl ----------------------------------------------------------------------------
 dnl Build macros
 dnl ----------------------------------------------------------------------------
 
-dnl
-dnl PHP_BUILD_THREAD_SAFE
-dnl
-AC_DEFUN([PHP_BUILD_THREAD_SAFE], [m4_warn([obsolete],
-  [The macro 'PHP_BUILD_THREAD_SAFE' is obsolete. Set 'enable_zts' manually.])
-  enable_zts=yes])
-
 dnl
 dnl PHP_REQUIRE_CXX
 dnl
@@ -1518,31 +1491,6 @@ AC_DEFUN([PHP_CHECK_FUNC],[
   esac
 ])
 
-dnl
-dnl PHP_TEST_BUILD(function, action-if-ok, action-if-not-ok [, extra-libs [, extra-source]])
-dnl
-dnl This macro checks whether build works and given function exists.
-dnl
-AC_DEFUN([PHP_TEST_BUILD], [m4_warn([obsolete],
-  [The macro 'PHP_TEST_BUILD' is obsolete. Use AC_* macros.])
-  old_LIBS=$LIBS
-  LIBS="$4 $LIBS"
-  AC_LINK_IFELSE([AC_LANG_SOURCE([
-    $5
-    char $1(void);
-    int main(void) {
-      $1();
-      return 0;
-    }
-  ])],[
-    LIBS=$old_LIBS
-    $2
-  ],[
-    LIBS=$old_LIBS
-    $3
-  ])
-])
-
 dnl ----------------------------------------------------------------------------
 dnl Platform characteristics checks.
 dnl ----------------------------------------------------------------------------
@@ -2039,25 +1987,6 @@ AC_DEFUN([PHP_INSTALL_HEADERS],
   ])
 ])
 
-dnl
-dnl PHP_AP_EXTRACT_VERSION(/path/httpd)
-dnl
-dnl This macro is used to get a comparable version for Apache.
-dnl
-AC_DEFUN([PHP_AP_EXTRACT_VERSION], [m4_warn([obsolete],
-  [The macro 'PHP_AP_EXTRACT_VERSION' is obsolete. Use 'apxs -q HTTPD_VERSION'])
-AS_IF([test -x "$1"], [
-  ac_output=$($1 -v 2>&1 | grep version | $SED -e 's/Oracle-HTTP-//')
-  ac_IFS=$IFS
-IFS="- /.
-"
-  set $ac_output
-  IFS=$ac_IFS
-
-  APACHE_VERSION=$(expr [$]4 \* 1000000 + [$]5 \* 1000 + [$]6)
-])
-])
-
 dnl
 dnl PHP_CONFIG_NICE(filename)
 dnl