diff --git a/test/defaults b/test/defaults
index 14cd6742..fdb75af2 100644
--- a/test/defaults
+++ b/test/defaults
@@ -8,14 +8,14 @@ declare -gA latest_composer
 # Defaults for scalingo-22:
 default_php["scalingo-22"]="8.1." # This one depends on the semver stable rule configuration
 default_nginx["scalingo-22"]="1.28."
-default_composer["scalingo-22"]="2.8."
-latest_composer["scalingo-22"]="2.8.12"
+default_composer["scalingo-22"]="2.9."
+latest_composer["scalingo-22"]="2.9.2"
 
 # Defaults for scalingo-24:
 default_php["scalingo-24"]="8.4."
 default_nginx["scalingo-24"]="1.28."
-default_composer["scalingo-24"]="2.8."
-latest_composer["scalingo-24"]="2.8.12"
+default_composer["scalingo-24"]="2.9."
+latest_composer["scalingo-24"]="2.9.2"
 
 
 test::defaults::classic() {
diff --git a/test/fixtures/composer-2.9.2/composer/composer.json b/test/fixtures/composer-2.9.2/composer/composer.json
new file mode 100644
index 00000000..6cdc38dd
--- /dev/null
+++ b/test/fixtures/composer-2.9.2/composer/composer.json
@@ -0,0 +1,9 @@
+{
+    "extra": {
+        "paas": {
+            "engines": {
+                "composer": "2.9.2"
+            }
+        }
+    }
+}
diff --git a/test/fixtures/composer-2.9.2/composer/composer.lock b/test/fixtures/composer-2.9.2/composer/composer.lock
new file mode 100644
index 00000000..b3a75590
--- /dev/null
+++ b/test/fixtures/composer-2.9.2/composer/composer.lock
@@ -0,0 +1,18 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "5aac55146c9cabad521141fa4188bbda",
+    "packages": [],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": {},
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": {},
+    "platform-dev": {},
+    "plugin-api-version": "2.6.0"
+}
diff --git a/test/fixtures/composer-latest b/test/fixtures/composer-latest
index 328db78b..86eeaefd 120000
--- a/test/fixtures/composer-latest
+++ b/test/fixtures/composer-latest
@@ -1 +1 @@
-composer-2.8.12
\ No newline at end of file
+composer-2.9.2
\ No newline at end of file
diff --git a/test/fixtures/php-8.5/composer/composer.json b/test/fixtures/php-8.5/composer/composer.json
new file mode 100644
index 00000000..1659532c
--- /dev/null
+++ b/test/fixtures/php-8.5/composer/composer.json
@@ -0,0 +1,5 @@
+{
+    "require": {
+        "php": "~8.5"
+    }
+}
diff --git a/test/fixtures/php-8.5/composer/composer.lock b/test/fixtures/php-8.5/composer/composer.lock
new file mode 100644
index 00000000..6b0f8281
--- /dev/null
+++ b/test/fixtures/php-8.5/composer/composer.lock
@@ -0,0 +1,20 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "376fc9f81f2d9ad80d18e90efda04653",
+    "packages": [],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": {},
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": {
+        "php": "~8.5"
+    },
+    "platform-dev": {},
+    "plugin-api-version": "2.6.0"
+}
diff --git a/test/fixtures/php-8.5/optional_builtin/composer.json b/test/fixtures/php-8.5/optional_builtin/composer.json
new file mode 100644
index 00000000..90cf9165
--- /dev/null
+++ b/test/fixtures/php-8.5/optional_builtin/composer.json
@@ -0,0 +1,11 @@
+{
+    "require": {
+        "php": "~8.5",
+        "ext-calendar": "*",
+        "ext-ftp": "*",
+        "ext-gettext": "*",
+        "ext-gmp": "*",
+        "ext-sodium": "*",
+        "ext-tidy": "*"
+    }
+}
diff --git a/test/fixtures/php-8.5/optional_builtin/composer.lock b/test/fixtures/php-8.5/optional_builtin/composer.lock
new file mode 100644
index 00000000..1e13b8ba
--- /dev/null
+++ b/test/fixtures/php-8.5/optional_builtin/composer.lock
@@ -0,0 +1,26 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "117f5b234daeb22fb27fa5cbd5b95676",
+    "packages": [],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": {},
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": {
+        "php": "~8.5",
+        "ext-calendar": "*",
+        "ext-ftp": "*",
+        "ext-gettext": "*",
+        "ext-gmp": "*",
+        "ext-sodium": "*",
+        "ext-tidy": "*"
+    },
+    "platform-dev": {},
+    "plugin-api-version": "2.6.0"
+}
diff --git a/test/php85 b/test/php85
new file mode 100644
index 00000000..44606ade
--- /dev/null
+++ b/test/php85
@@ -0,0 +1,77 @@
+#!/usr/bin/env bash
+
+readonly default_builtins_extensions_85=(
+	"bcmath" "bz2" "Core" "ctype" "curl" "date" "dom" "exif" "fileinfo"
+	"filter" "gd" "hash" "iconv" "intl" "json" "libxml" "mbstring" "mysqli"
+	"mysqlnd" "openssl" "pcntl" "pcre" "PDO" "pdo_mysql" "pdo_pgsql"
+	"pdo_sqlite" "pgsql" "Phar" "posix" "random" "readline" "Reflection"
+	"session" "shmop" "SimpleXML" "soap" "sockets" "SPL" "sqlite3" "standard"
+	"tokenizer" "xml" "xmlreader" "xmlwriter" "xsl" "Zend OPcache" "zip" "zlib"
+)
+
+readonly default_pecl_extensions_85=(
+	"apcu" "mongodb" "redis"
+)
+
+readonly optional_builtin_extensions_85=(
+	"calendar" "ftp" "gettext" "gmp" "sodium" "tidy"
+)
+
+test::php85::classic() {
+#
+# Test a deployment of a classic app (not using Composer)
+# Specifying we want PHP 8.4.x via environment
+#
+
+	PHP_VERSION="8.5"
+	export PHP_VERSION
+
+	test::utils::setupFixture "defaults/classic"
+	test::helpers::classic_deploy \
+		"8.5." \
+		"${default_nginx["${STACK}"]}"
+}
+
+test::php85::composer() {
+#
+# Test a deployment of a PHP app using Composer
+# Specifying we want PHP 8.4.x via composer.json
+#
+
+	test::utils::setupFixture "php-8.5/composer"
+	test::helpers::composer_deploy \
+		"8.5." \
+		"${default_nginx["${STACK}"]}" \
+		"${default_composer["${STACK}"]}"
+}
+
+test::php85::extensions::default() {
+#
+# Test the presence of default enabled built-in extensions.
+#
+
+	test::utils::setupFixture "php-8.5/composer"
+
+	test::utils::compile
+	test::helpers::enter_prod
+
+	local extensions=("${default_builtin_extensions_85[@]}")
+	extensions+=("${default_pecl_extensions_85[@]}")
+
+	test::helpers::enabled_extensions "${extensions[@]}"
+}
+
+test::php85::extensions::optional_builtin() {
+#
+# Test the presence of available built-in extensions that are not
+# enabled by default.
+#
+
+	test::utils::setupFixture "php-8.5/optional_builtin"
+
+	test::utils::compile
+	test::helpers::enter_prod
+
+	test::helpers::enabled_extensions "${optional_builtin_extensions_85[@]}"
+}
+
diff --git a/test/tests b/test/tests
index 4b5dada7..02da4d63 100755
--- a/test/tests
+++ b/test/tests
@@ -8,6 +8,7 @@ source "$( pwd )/test/php81"
 source "$( pwd )/test/php82"
 source "$( pwd )/test/php83"
 source "$( pwd )/test/php84"
+source "$( pwd )/test/php85"
 source "$( pwd )/test/php"
 source "$( pwd )/test/composer"
 source "$( pwd )/test/nginx"
@@ -42,6 +43,12 @@ suite_addTest test::php84::composer
 suite_addTest test::php84::extensions::default
 suite_addTest test::php84::extensions::optional_builtin
 
+# PHP 8.5
+suite_addTest test::php85::classic
+suite_addTest test::php85::composer
+suite_addTest test::php85::extensions::default
+suite_addTest test::php85::extensions::optional_builtin
+
 # PHP
 suite_addTest test::php::composer_over_lower_classic
 suite_addTest test::php::composer_over_higher_classic